As far as I know, Jetfire, Arcee, Sideways, Demolisher, Alice, and The Fallen. Not sure if I skipped anyone
Edit: Arcee didnt die, one of the sisters did however.
Edit 2: Ravage, Rampage, Grindor, Scorponok and Mixmaster all appeared to be killed with varying degrees of certainty. Several other Decepticons weren't seen after the area was bombed.
The following have died: Sideways, Demolishor, Scrapmetal, Alice the Pretender, Grindor, Skipjack, Ravage, Scorponok, an Insecticon, Arcee, Mixmaster, Long Haul, Jetfire and the Fallen. Optimus Prime and Sam Witwicky also die but return to life by the end of the movie. Now you know.