This is a tough call since both games haven't been released.But from what i've seen from both games so far,they both look promising.However i would go with Need for Speed Underground 2.I can't exactly tell you why but after playing the Juiced demo,i don't know,it didn't feel right.Juiced looks good and has plenty of tuning options but so does NFS U2.It's going to be close that's for sure but i pick NFS U2 as the winner.It can only get better after the first Underground game and watching the trailer it sure looks that it has improved a lot.