My life motto is "Expect nothing, and you won't be disappointed." It's hard to do that sometimes (like all the hype around Zelda and Gears of War, thankfully they turned out alright), but I think I handle it usually.
I can't think of many games recently that i've actually played that I've been disappointed with. Phantasy Star Universe is the only one that really comes to mind, though it's not that bad. I tend to stay away from bad games.
Also, DBZ Budokai 3, DBZ Tenkaichi Budokai 2 for Wii and the 2 portable Supersonic Warriors games are all awesome DBZ games. Play 'em.