I liked the first, but the second one had alot of flaws.
Reason why I didn't like the movies that much:
Sam Witwicky felt to big a character.
The romance between Sam and whats-her-face, I came for giant robots. Not romance.
Sam's family. More specificaly, his mother. Gawd was she stupid and annoying.
The dogs humping... yeah...
And number 2, felt very boring and slow paced.
Also, the battle between Optimus and The Fallen, was anticlimactic. This is the guy who bossess Megatron around, a powerful evil robot... and Optimus drop kicks his ass faster then most enemies.