Ok, here goes. First of all when you talk about "playing games" in the bedroom, who needs a TV
Kidding aside, while the 29" has the size, which always adds to the enjoyment of video games, bigger may not be better here. With the 21", not only do you get the newer and better flat screen tech but you also get component vid as well as S-vid.
So, that gives you better tech with more versatility and less viewing area. The 29" gives you more viewing area.......period. It's your choice but given the specs and that's it's in a bedroom, I'd choose the 21". But either way, I'm sure you'll enjoy it.
Mike T.