If you already have a PS3 why would you stop playing it? Also I don't if you but consoles solely for you it doesn't matter which you choose but if you think you can invest to have fun with more people then maybe you should reconsider some choices. There are games in my library I would've never bought for myself but since I'm not alone and yes I like to have fun with the girlfriend and nieces and the family I have bought these games and don't care if I "look" stupid it's all about the fun.
Also, just because you can't name 10 games you ultimately want on one console doesn't mean they don't exist. You always get to find more games you never knew about. Friends also have games you never thought of buying but to play with them you do and you realise there is more into gaming than "single player exclusives".
About the price. Buying a 360 with Kinect at 199$ is almost cheaper than buying a Wii at 99$ Remember you have to pay for those extra controllers and nunchucks. Also someone suggested you to get a decent PC to run Gears of War 1 and if you like it then buy a 360... seriously... if you hate your 360 so much after you bought it just sell it it's in demand you won't lose much it'll be like you rented it.
I plan on buying a PS3 to play the Uncharted series but if I do so, nothing prevents me from enjoying my 360 anymore and it'll get me a cheap Blue Ray. Most of the games I play are multiplat but I'm sure I'll find games I like on PS3... I'm not a Sony fan but some functionalities will get me to buy one... 199$ is cheap.
