I also agree, this movie was terrible for a variety of reasons, which I will rant about shortly.
Also, his amazing record aside, Frank Welker, according to Billy West, apparently can do the sounds for an entire flock of geese in one take.
I think some of the funniest riffs were in Soundwave's scenes (the part where he was taking over the other satellite almost had me in tears. I mean I kind of saw it coming, but that only seemed to make it funnier.) The riffs were over a lot of the dialogue, but I didn't mind at all. A lot of Bay-bashing, but it is well earned, they also point out a lot of things that are just very true (Was there a small army of Megatrons at the end of the movie? Who actually could tell who was who?). The "Go Go Go" thing did get old, but remember that you would have gotten the exact same amount from LeBeef if you watch it un-riffed just stretched out over a longer period of time.
On to the ranting:
1. the Fallen was a joke
2. the Doomsday Weapon was a joke
3. some of them can magically teleport now
4. did they even mention Energon in the first movie?
4. the Presidential aid and Jetfire were only in the movie to spout exposition or to act as a MacGuffin
6. MICHAEL BAY SAVED SKORPONOK IN THE FIRST FILM FOR A THREE AND A HALF SECOND CAMEO?
(Yes, I'm also a Beast Wars fan, which featured no humans at all, and yes, the line lengths above were carefully reordered because I'm neurotic)
The most horrifying thought of all is that there will be a sequel to THIS movie.
Alright, the end of this rant in a moment.
The most irritating thing is that they almost, just barely, started to introduce some depth with Jetfire but abandoned it for a comical rant and a cheap fart joke. HE SWITCHED SIDES, which means that all Decepticons are not necessarily evil, and yet Optimus and all the 'Good Guys' seem to enjoy tearing their heads in two more than trying to talk with them. The sides, of any argument, should never be so incredibly distinct. The was a thin sliver of hope for something redeeming in this movie's plot that
LITERALLY up and vanished like a fart in the wind.
To sum it all up: (In Soundwave/Dr. Claw Voice)
CURSE YOU, MICHAEL BAY! CURSE YOU!