hey there,
best thing to do: visit gamespot, or IGN, and get game ratings... thats what i do before putting any consideration into buying a game.
they have ingame videos, trailers, and much more.... if you don't know already...
pay the sites a visit before investing in the games. they also have alternatives if games don't meet certain requirements (Visual, sound, gameplay, presentation etc...)
hope this helps, and enjoy the sites
Dane