Rachet, Megatron, Prowl, Gears, Optimus, Thundercracker, Hardshell, Brawn, Ironhide, Wheeljack, Windcharger, Hound, Huffer, Trail Breaker, Red Alert, Sideswipe, Skywarp, Shockwave, Sunstreak, and Starscream are some of the ones I know who died
My headcanon is that all of the ones who were never confirmed to die or were planned to die lived on, I made a whole story around that because a lot of those guys never got much screen time. also, Smokescreen died.
Yeah I forgot to mention him. And what of Cosmos, Powerglide, Seaspray, that one pacifist who found the Golden Lake, and the others who were in Season 2 but not in the movIe? Also, did I forget to mention the ones who tried to fight Devastator and failed horribly?