Play money is stupid in partypoker, bodog, pacific, whatever. People do the dumbest things like push all in with 3-8 because you can just hit the "get more money" button later on.
Edit: I like how Bodog lets you play 10-player SnGs with play money, and you can only get $1000 play money at once. If you move up to $5000, you can play at a better table with the more pro play money people who are probably more serious. Either way, SnG is better because you can watch the idiots do stupid things, and possibly cash in on that. However, if you're dealing with some lucky mofo who's eliminating idiots who are pushing all in with 3-8, then that will suck.
Bottom line, go for money. Yahoo games is pathetic. When you play limit with $2 big blinds and you have $1000, that's kinda jacked. People will just keep raising because obviously a $32 pot is chump change.