Sub groups are often a highlight of Transformers; usually they're a team of 'bots or 'Cons with a specific theme. The Predacons in G1 were a team of beast-formers; the Dinobots are dinosaurs (No shit Sherlock); Vehicons totally non-organic drones for Beast Machines Megatron to use to exterminate organic life; Seekers all jets and Starscream repaints. Aerialbots, Seacons, Combaticons, Stunticons, Wreckers, Fuzors, the list goes on and on and on and on (Strangers, waiting...). Do you have a favorite? It can be specific to a continuity; the Beast Machines Vehicons are entirely different from the Prime Vehicons. Or you could just prefer how the G1 Dinobots were over how the Animated Dinobots. It depends on your preference, but you can count the Maximals and Predacons in Beast Wars, despite them technically being the "main" factions in the show. My personal favorites: The Animated Seekers, the G1 and Animated Dinobots, and the Beast Machines Vehicons as my top favorite. The Beast Machines Vehicons, despite not being good guys like the Maximals, were always the most memorable members of the show's cast. Thrust was a cool lone wolf type, Jetstorm was cocky and snarky, Obsidian and Strika were two badass and dangerously intelligent war generals, and Tankor was a comically dumb brute ("I will SMAAAAASH mouse-bot!") before becoming, well, you know.