Here they are! Those among the roster that have more than just 2 forms!

Backrow:
Trypticon (Battle-station mode), Tantrum, Headstrong, Divebomb, Rampage, Razorclaw (these 5 were known as Predacons)

Next row (short Row):
Motormaster, Onslaught (these 2 were leaders of Stunticons and Combaticons respectively, and Motormaster is one who later suffered an almost-permanent namechange since he was a black rig and a badguy, he eventually was retitled: Nemesis Prime)

Next next Row:
Wildride, Deadend, Breakdown, Hook, Bonecrusher, Scavenger, Mixmaster, Longhaul, Scrapper

Last Robot Row:
Vortex, Brawl, Swindle, Blastoff, Fulltilt, Dragstrip

Front Row:
Blitzwing (Jet mode), Octane (Jet Mode, Astrotrain (Locomotive mode)