Just do what I did and get both
Ummm....might set you back about a good $850 (not including tax), but it's all worth it in the end.
I can't really vote for one or the other though. I love my PS3 because I imported it from Japan, and I can play my PS2 imports on it. No more kinfe trick for me!! I love my Wii because it's like the only video game system my parents actually play. The last time I remember my stepdad playing a video game was a Tiny Toons video game on Game Boy back in the mid 90's. The last time I remember my mom playing a video game was in the mid 90's as well....it was a TMNT game on the SNES...the one where they went through time, and you could throw the Foot Soldiers into the screen (nostalgia). And the Pokemon game on the Wii is fun for a bit too. Wii Sports is so cool!
OK, back to the topic...I like em both, and can't really vote