NES
A - Carpenter...?
B - Donkey Kong
C - Tennis and (Mike Tyson's) Punchout!!, possibly more
Extra - I think it was top, bottom, top

SNES
A - Iggy Koopa. Knock him off his platform into the pit of lava.
B - Donut Plains
C - The world map does a color swap and some of the enemies change appearance (koopas have Mario faces as shells, piranha plants look like pumpkins, etc.)
Extra - I have no idea, I didn't really play DKC besides the first...

N64
A - Super Mario 64
B - Yoshi
C - God, I know this, and I'm going to kick myself when someone posts the right answer...
Extra - I can't remember...

GCN
A - Four? I think it was 4 through 7.
B - One. Thousand-Year Door.
C - No idea.

NES:
a) What was Mario´s first job? - His backstory has him as a plumber. Don't recall if that was the original backstory or not.
b) In which game Mario made his gaming debut? - Donkey Kong
c) In which kind of a game Mario served as a referee? (Sports) - Soccer, specifically Mega Man Soccer EDIT: Blanked on Punch-out. And I might be misremembering on Mega Man Soccer, which was an SNES game anyway. Carry on, nothing to see here.
EXTRA:
This picture is part of map of stage 7-4 in original Super Mario Bros. In the game, you can´t just go under all those platforms, you have to use a certain code, like first use the highest platform, then middle and so on. If done incorretly, this part of the map will loop endlessly untill you get the code right. Question is, what is the code to be used?
http://img184.imageshack.us/my.php?image=mario74hn8.png

Haven't a clue. Might have known at one point.

SNES:
a) What is the name of the first boss in Super Mario World? How do you beat him/her? - I believe it's Lemmy Koopa, and you have to bounce on his head to spin him off the rocking platform.
b) What is the name of the second land in Super Mario World? - Donut Plains
c) What special thing can you unlock by beating all extra levels of the Star Road in Super Mario World(Again!)? - Beating the Star Road unlocks the Special Zone. Beating the Special Zone unlocks the palette swap.
EXTRA: In which Donkey Kong Country game Mario appears as a guest and where? - Never played DKC. Dunno.

Nintendo64: - Never had N64, so I never played it.
a) In which game Mario made his 3D debut?
b) Which appers in the Super Mario 64: Luigi or Yoshi?
c) What does Mario say if gets kicked out of a stage(loses) in Super Mario 64?
EXTRA: In Super Mario 64, stages are paintings which Mario has to jump in. What special thing happens to the painting that leads to last stage of the game when you aproach it?

GameCube:
a) How many Mario Party games has been released to GC? - Three: Mario Party 5, 6, and 7. Mario Party 8 is the first released for Wii.
b) How many Paper Mario games has been released to GC? - Just one. Paper Mario was an N64 game, later released on Virtual Console, Paper Mario: The Thousand Year Door was a GC game, and Super Paper Mario was a Wii game.
c) How much space does one Mario Party 5 save take? - I don't recall.

I referred to palette swap and with star road extra levels I meant extra zone but good, fantastic!

NES:
a) What was Mario´s first job?
Carpenter
b) In which game Mario made his gaming debut?
Donkey Kong
c) In which kind of a game Mario served as a referee? (Sports)
Punch-Out!! (Boxing), and Tennis (..tennis )
EXTRA:
This picture is part of map of stage 7-4 in original Super Mario Bros. In the game, you can´t just go under all those platforms, you have to use a certain code, like first use the highest platform, then middle and so on. If done incorretly, this part of the map will loop endlessly untill you get the code right. Question is, what is the code to be used?
http://img184.imageshack.us/my.php?image=mario74hn8.png
High-low-high, I thought.

SNES:
a) What is the name of the first boss in Super Mario World? How do you beat him/her?
Iggy Koopa, throw him into the lava
b) What is the name of the second land in Super Mario World?
Donut Plains or Valley, iirc.
c) What special thing can you unlock by beating all extra levels of the Star Road in Super Mario World(Again!)?
Special zone.
EXTRA: In which Donkey Kong Country game Mario appears as a guest and where?
No idea.

Nintendo64:
a) In which game Mario made his 3D debut?
Super Mario 64 >_>
b) Which appers in the Super Mario 64: Luigi or Yoshi?
Yoshi
c) What does Mario say if gets kicked out of a stage(loses) in Super Mario 64?
Oooh! Mama Mia!
EXTRA: In Super Mario 64, stages are paintings which Mario has to jump in. What special thing happens to the painting that leads to last stage of the game when you aproach it?
The stairs never end.

GameCube:
a) How many Mario Party games has been released to GC?
4
b) How many Paper Mario games has been released to GC?
1
c) How much space does one Mario Party 5 save take?
No idea.

NES:
a) What was Mario´s first job?
I'm tempted to say Carpenter, but I'm not 100% sure.

b) In which game Mario made his gaming debut?
Donkey Kong (Arcade)

c) In which kind of a game Mario served as a referee? (Sports)
He was in Punch out as the ref.

d) What kind of a game Dr. Mario is?
Puzzle Game.

e) Who made his/her gaming debut in Mario Bros.?
Bowser/King Koopa? I don't know if Peach counts since she was "pauline" in Donkey Kong.

EXTRA:
This picture is part of map of stage 7-4 in original Super Mario Bros. In the game, you can´t just go under all those platforms, you have to use a certain code, like first use the highest platform, then middle and so on. If done incorretly, this part of the map will loop endlessly untill you get the code right. Question is, what is the code to be used?
http://img184.imageshack.us/my.php?image=mario74hn8.png

I'm tempted to say Top, Middle, Bottom, but I'm pretty sure it's Top, Middle, Top

SNES:
a) What is the name of the first boss in Super Mario World? How do you beat him/her?
Iggy Koopa- knock him off the see-saw platform

b) What is the name of the second land in Super Mario World?
Doughnut Plains?

c) What special thing can you unlock by beating all extra levels of the Star Road in Super Mario World(Again!)?
The Characters get new sprites and the world map changes color.

d) What is the name of Super Mario Worlds sequel?
Yoshi's Island

EXTRA: In which Donkey Kong Country game Mario appears as a guest and where?
Donkey Kong Country 2: Diddy's Kong Quest- He's on Cranky's Video Game Heroes above Yoshi and Link.

Nintendo64:
a) In which game Mario made his 3D debut?
Mario 64, but a SNES 3D Mario game was never released.

b) Which appers in the Super Mario 64: Luigi or Yoshi?
Yoshi- Top of castle

c) What does Mario say if gets kicked out of a stage(loses) in Super Mario 64?
Mamamia

d) When was the first Mario Party released?
Yikes... I'm going to guess 1999 but it might be 1998.

EXTRA: In Super Mario 64, stages are paintings which Mario has to jump in. What special thing happens to the painting that leads to last stage of the game when you aproach it?

Are you talking to the NeverEnding staircase (until you have enough stars)?

GameCube:
a) How many Mario Party games has been released to GC?
4, 5, 6, and 7. Four

b) How many Paper Mario games has been released to GC?
Only one. Thousand Year Door (my favorite GC game).

c) How much space does one Mario Party 5 save take?
5 Blocks (I had to turn on my Gamecube to double check, but my initial guess was 5, so I technically didn't cheat at all during this).

d) In Mario Smash Football, what is the name of the cup in Battle Mode?
Don't you mean Mario Strikers (American name)? If you tell me which one (Wii or GC), I might be able to answer.

e) What is the name of the Mario baseball game?
Mario Superstar Baseball

NES:
a) Plumber
b) Donkey Kong
c) Mike Tyson's Punch-Out! is the main one. And some other tennis game, so, Boxing and Tennisl.
d) Well, it's part of the puzzle genre. Not quite sure what you meant by this question.
e) Luigi
EXTRA:
Bottom, middle, top.

SNES:
a) Iggy, and you have to jump on his head and then knock him into the lava.
b) Donut Plains
c) Another secret world with 8 levels, IIRC, it was called Special Zone.
d) Yoshi's Island
EXTRA:
Donkey Kong Country 2, on the podium in Cranky's house.

Nintendo64:
a) Super Mario 64
b) Yoshi
c) Mama-Mia!
d) Which region? It came out in 98 in Japan, and I think 99 in America and Europe.
EXTRA: What? The last stage of the game doesn't have a painting.

GameCube:
a) Do you mean how many Mario Party games have been released up until this point, or how many have appeared on the Gamecube? If the latter, then it's four. Mario Party 4, 5, 6, and 7.
b) As above, if the latter, then one... The Thousand Year Door.
c) 5 Blocks
d) There's more than one. ._.
e) Mario Superstar Baseball

...to the painting which has princess Peach in it. When aproach it, Peach´s image transforms to Bowser´s.

Luigi

NES:
a) What was Mario´s first job? Carpenter
b) In which game Mario made his gaming debut? Donkey Kong
c) In which kind of a game Mario served as a referee? (Sports) Punch out and Tennis
d) What kind of a game Dr. Mario is? Puzzle
e) Who made his/her gaming debut in Mario Bros.? Luigi
EXTRA:
This picture is part of map of stage 7-4 in original Super Mario Bros. In the game, you can´t just go under all those platforms, you have to use a certain code, like first use the highest platform, then middle and so on. If done incorretly, this part of the map will loop endlessly untill you get the code right. Question is, what is the code to be used?
http://img184.imageshack.us/my.php?image=mario74hn8.png
um....High middle High

SNES:
a) What is the name of the first boss in Super Mario World? How do you beat him/her? I think...iggy and you bounce on his head til he falls in the lava
b) What is the name of the second land in Super Mario World? Donut Plains
c) What special thing can you unlock by beating all extra levels of the Star Road in Super Mario World(Again!)? Special zone and if you beat all those levels you get a cool remake (I call it a remake)
d) What is the name of Super Mario Worlds sequel? Yoshi's Island
EXTRA: In which Donkey Kong Country game Mario appears as a guest and where? I think number 3 because I remember the game that was being played in the save cave was like Peach's castle

Nintendo64:
a) In which game Mario made his 3D debut? Super Mario 64 (duh)
b) Which appers in the Super Mario 64: Luigi or Yoshi? Yoshi
c) What does Mario say if gets kicked out of a stage(loses) in Super Mario 64? *Mario falls* Mamma Mia...
d) When was the first Mario Party released? ...dont know ><
EXTRA: In Super Mario 64, stages are paintings which Mario has to jump in. What special thing happens to the painting that leads to the first Bowser stage when you aproach it? The first bowser stage? Thats when the picture of peach changes to bowser

GameCube:
a) How many Mario Party games has been released to GC? 4
b) How many Paper Mario games has been released to GC? 1
c) How much space does one Mario Party 5 save take? think 4 blocks (or w/e its called)
d) In Mario Smash Football, what is the name of the cup in Battle Mode? dunno
e) What is the name of the Mario baseball game? Mario Superstar Baseball
I´ll get more questions some time.[/quote]

a) Plumber.
b) Donkey Kong.
c) Mike Tyson's "Punch-Out" (Boxing)
d) Puzzle.
e) Luigi, Peach, Toad, and "King Koopa".
EXTRA:

Top, Middle, Top.

SNES:
a) Iggy Koopa. Jump on him and he'll slide towards whatever side the rocking platform is leaning towards. Make him fall off either side, into the lava.
b) Donut Plains.
c) You unlock the "Special" World. Known as this because of the word "Special" on the map screen area.
d) Super Mario RPG.
EXTRA: Donkey Kong Country 2, in Cranky's hut.

Nintendo64:
a) Super Mario 64. (However, some argue that Super Mario RPG was actually the "3-D" game he first appeared in)
b) Yoshi, by collecting all stars, and using the cannon outside to go to the top of the castle.
c) Mama-mia!
d) 1999.
EXTRA: It'll slowly change it's image into a Bowser-icon, but before you can jump in, the trap-floor stops you and takes you to the level.

GameCube:
a) 3.
b) 1.
c) 24 blocks.
d) Star Cup
e) Mario Superstar Baseball