PC. I've played on PC for most of my life and for a time was big into overclocking and tinkering but now, having gotten a PS3 a couple of years ago and a 2DS this year I've really lost a lot of enthusiasm for it, where before I was PC-only and didn't see the need to branch out. Two reasons mainly: namely Steam's poor achievements system (I *love* the Playstation trophies and they're more nicely done than Steam's), and also the constant focus on performance and upgrading. I by habit keep a framecounter running when I play on PC, but don't think about things like that when it comes to the PS3 or 2DS. Plus the reclining chair and TV are more comfortable than the PC. I'm still keeping it and not going to sell it or anything because it's still way too useful for CRPGs, visual novels and multiplats as well as other non-gaming things, but my heart isn't really there right now. I just want to be able to play the games I want to play, wherever they may be and I've learned the lesson that sticking to one platform is limiting myself too much.
Non portable systems. This is a byproduct of the fun I've had with the PS3 and then the 2DS. Since there's only 1 TV it means I can't play when others want to use it, so I've had situations where I've lost progress (1h30m in Persona 4
) thanks to having to quit without warning. The thing though, is that being portable eliminates that and also makes it possible to play while in the car, waiting in line, or even doing things like cooking, and that + sleep mode make it easy to chip through long games - helpful since I like RPGs quite a lot. It's made me greatly appreciate a system that is portable and, again, I wonder why I didn't look into them several years ago.