Sega!
If you were given the choice of making one of the big 3 die in order to get Sega back in the system business would you? I would personally kill off Microsoft because as of now they are my least favorite of the 3. I would want Sega back with the hopes that they would take more risks and bring some of their older IP's back.
I wouldn't want Nintendo gone because I like their innovations in terms of systems. I like the 3D in the 3DS, and I like the idea behind the Gamepad (even though I never tried it) and I wouldn't sacrifice either innovation for more powerful tech. Plus, I feel if Nintendo went 3rd party they wouldn't try as hard or just stop all together.
I considered "sacrificing" Sony in this hypothetical situation for my own greed of having Sony games go 3rd party. I found this to be wrong though as Sony has enough good IP's to warrant their place in the system market. They wouldn't deserve it IMO. On the other hand, they forced Sega out and I don't think they deserved it...well game-wise at least. They did make some pretty dumb mistakes.
Anyway, I would kill off Microsoft, you?
