Most of my PS2 (60%) and Gamecube (30%) games were all used. I haven't bought any used Wii games yet. Wii games aren't as expensive as games use to be in Canada so it doesn't seem like such a bad deal when buying new. I have a few used DS games (mostly one's which were hard to find). Otherwise I prefer new as I know I take care of my discs etc.

I sometimes wait for prices to drop.  Problem with Nintendo games is that they rarely ever drop in price. 

If it's a must-have game that I'm looking forward to, I'll buy it first-day or as soon as I can. Games I want but I'm in no need to get immediately, I will try to buy cheaply off eBay or Amazon (Lair for $31 when I finally got it from Amazon). It seems it takes much, much longer for a game to go budget price this generation than it has in the past. I always buy new. Call me weird or a perfectionist, but I would rather have something pristine so I can keep it pristine.

i buy all my games first day and new

 I think it is the nature of it being a new generation.  PS2 was like that the first couple of years too...  Older the generation gets, the more accessable used games will be, and as the library grows, the less time it will take for new games to go budget.