i havent played mine very much, but its because ive been really busy with school and stuff and just dont get much time to play that or the 360. when i do get time to play i enjoy it though.
id get the wii play game simply for the fact that you get an extra wiimote with it. another wiimote is like 40 bucks i think. the game is 50, so look at it as getting a game for 10 bucks
i dont think there are as many high profile games for the wii, but ive liked every game ive played on it so far.
the wii is for people of all ages too.
PLUS you can download and play NES, SNES, N64, genesis, neo geo and tg16 games on it too.
i got a 360, because there are way more sweet games for the 360, but i dont think ive played a bad wii game yet.
PS: if you get bored with mario party, then you're doing it wrong. add alcohol. it makes a GREAT drinking game.