This is one of my favorites as well! Especially when pulling up to the Decepticon batteships.
Plus, I love the sound of Sentinel's blade when he swings it!

Alot of my other favorites came from TF1 actually.

-the EMP explosion sound from Blackout.
-the entire Starscream vs. Ironhide and Ratchet scene sounded AMAZING (esp. when SS transforms)
-Frenzy's rants
-All of the artillery shells and explosions during the Brawl vs. Ironhide, Ratchet, and Jazz scene

 

The sound of Ravage's guns firing.

 

Oh yeah! They remind me of a rattlesnake's, uh, rattle.   Cool detail.

 

I've always loved the sound that Blackout makes during the base attack in TF1, as he's turning around from being shot by Fig. As soon as I heard that noise, I knew I was going to love that movie lol.

Also, the Cybertronian talking that the Protoform says as he kidnaps Sam's parents in the second movie.

Oh yeah, and pretty much any noise made by Frank Welker. Like Ravage's growls, and Soundwave's voice.

 

i like the transformation sounds the most, especially the ones between the Autobots in the first movie. i think my favorite has to be the one in mission city when Jazz transforms and jumps on top of Brawl.

 

I like the sound of Jazz transforming anf attacking Brawl.

 

first off, what an interesting question!

as for my favourite sounds ... watched DOTM again last night, and the one that always really stands out for me is when the Wreckers start attacking Shockwave as a distraction, and it switches to a shot of Shockwave putting up his shield, and he makes this like trumphet/elephant sound, but in a robotic kinda way ... it's just really cool to me.  

and any time Shockwave or Soundwave talks is just music to my ears  

still with DOTM, i'd have to include Starscream's line when he's about to attack the Xanthium and it's panning away from the closeup of his optics. i have no idea what he's saying but it sounds cool

oh yes! very good ones!

which reminds me ... Optimus cocking his gun in DOTM and the bullet falling.

 

All the transformation sounds and weapons firing for one. And the sound of Optimus flying through the air and wrecking people in DOTM. Such a beautiful sound... shredding metal and explosions.

So beautiful...

 

I   everytime Prime makes that weird sound when Shockwave knocks him over in Chernobyl.

 

The sound that Blackout made that was recorded.

 

All of the tecnical chittering/ratcheting and sonic-blast-like sounds.

 

Blackouts EMP blast . Bonecrusher's transforming noise on the freeway . Devy's transforming sounds .

 

Yeah, I love that one as well! I keep wondering what that is but I love it. I thought it was just music or something! What do I know, right?

 

All of boncrusher's grunts and transformation
Sideswipes transformation
Soundwaves transformation
Cybertronian language

 

Optimus' voice. *blush*

 

This too. He has voice of a god!