Good:

- More Transformers screentime than the first movie. Just.
- Wheelie. A genuinely likeable character (:

Bad:

- The roommate. As Robzy said, he simply serves no purpose.
- The "hot" chick. Again, do we need her trying so hard to seduce Sam? She's just there for eye candy.
- The cookie scene. Useless, pointless. Sure it raised some laughs but it was also cringeworthy.
- Too many generic Decepticons getting their asses whupped. In the first film, "these things just don't die", in this film the Stormtrooper Effect is in full swing, and we see generic constructicons dying en masse.

I gave the first film 8/10... this one is about a 6 at the moment - my final verdict is still out, because the third film might tie things up for me, but it's nowhere near the first film at the moment. I don't hate it, but I'm not terribly fond. I'll watch it again and buy the DVD, but more because I'm a collector than because I love the film.