least polished game in my collection would have to be resident evil.
now, i'm not saying the game isn't really well done, but there are many things that i find really frustrating about this game.
the fmv's are sometimes choppy, which is really disappointing because the game was completely redone for ngc, not just a port. hit detection also seems to be slightly off. and my biggest complaint would have to be i find it really hard to push objects. especially when in a hurry because a zombie is chewing at my ankles. (example: i found it overly-difficult to push the statue off the 2nd floor of the dining room.)
on a slightly different note, the game is probably the least polished in my collection because i tend to only play tier one games. i just don't have enough time to waste playing spy hunter.