I'd say if you want more then 4-10 games to play right now, go for the PS2. If you want a system with more games coming out later down the road, get the Wii. As you asked this question over 2 weeks ago, have you got either?
I haven't gotten either yet, but Iwas just waiting for a good deal on a PS2. I'm not even looking for a Wii anymore. My birthday is on the 3rd so after I get lots of money, I'll probably just go out a buy one.