I would like to wake up in:
Zelda-I'd be the hero of time in a land of adventure and secrets. It would be awesome to find all these temples and fountains. I'd defeat Ganon, and then get Zelda to send me home.
Half-Life-I would get some guns, shoot some dudes, solve some physics puzzles, and be the most badass MIT graduate ever. I'd then use whatever physics equipment at my disposal to get home by the power of interdimensional teleportation.
Mario-Go through several colorful themed levels, save the princess, and then use whatever psychedelic means to get home.
Phoenix Wright-Learn lawyer skills that would get me disbarred instantly in real life, talk with interesting characters, use my absurd detective power to get evidence, and win some overly complex cases with loose logic. Get home by spirit-channeling, I guess.
Elite Beat Agents-Solve some people's problems by dancing to awesome songs and then sing and dance my way back home. I would then establish a real world Elite Beat Agents.
Trauma Center-Play some surgical Space Invaders, fight some ridiculous Darwinist cult that is trying to abolish medicine, and use the healing touch to rip a hole in spacetime to get home.
A dating sim-What else, bang some chicks. Hopefully Key would have made it so I could use whatever supernatural crap is available to get home. Then again, I could just stay and keep having sex, that would be good.
There are many games I would want to be in, but I'd probably want to go home when done.