(Actually you can only play as Luigi in Super paper Mario for the wii, and even then, you have to switch between Mario, Luigi, Peach and Bowser most if not ALL the time.)
A: 1. Paper Mario XD
Q: Be forced to play as Mario in a sonic game or be forced to play as Link in a Sonic game?

A: 2, def. 2. xD Although I'd feel sorry for Link, 'cause I think he'd have issues with the bots. :L And Lol If Mario and Sonic switched places, Mario'd be dead in like a day. And Sonic would've already saved the Princess, and made it so Bowser couldn't kidnap her again. C:
Q: Play as Link in a Mario game, or as Mario in a LoZ game? (Pfft. Bye Mario.)

(Here's a reenactment of how that would work: [you must login to view images])

A: Defs 1
Q: Play as Mario in Skyrim(He'd be dead the moment a Dragon or a Draugr saw him :L) or play as Sonic in Skyrim(Sonic would be able to outrun everything and get sidequests done in a split second. XD)

A: Option 2. xD
Q: Mario in a LoZ game, or Mario in a StH game? (either way, he'd lose. Even 'Butthead's smarter than he is.)

A: Mario in a LoZ game (meh :P)
Q: Mario or Luigi? (can't think of anything else xD)

A: Luigi. Definitely Luigi. xD
Q: Bowser or Egghead? :P

A:dunno what egghead is so bowser
Q:Define the word word.

A: A word is a thing made up of letters.
Q: Princess Peach or Princess Daisy?

A: Princess Peach (cuz not sure who princess daisy is XD)
Q: Princess Peach or Princess Zelda?

A: Princess Zelda. xD
Q: Princess Zelda:
[you must login to view images]
or Princess Sonia?:
[you must login to view images]

A: Princess Zelda :D (cuz she haz explosions and stuff and ofcourse shiek :3)
Q: Sonia in LoZ or Zelda in StH?

A: Hmm. Option 1. xD #GoSonia
Q: Be stuck playing a game you don't get to choose for the rest of your life, and only being able to chose one, or look at 'Buttnik's mom for half a second? xD

A: Option 1, Option 2 kinda scares me O_O xD
Q: spend the rest of the day with 'Buttnik' or with his mom? xD

(That's his mom. xD [you must login to view links] She's uuug-a-lyy! xD)
A: 'Buttnik. xD Then I can spend the rest of the day telling him how much better Sonic, and Tails, and his robots are better than he is, and who knows? He might kick me out before the day is over and I don't have to put up with him! :D
Q: Be stuck in a room with Mario doing Coconuts' job, or be stuck in a room with ;Buttnik's mom? xD

A: If I had to choose one, I'd have to say 1, it's allot better... and that's saying something...
Q:Mario party without Mario or Paper Mario (Paper Mario is better than Mario XD)