SC 2: Protoss (love Photon Cannon Rush)
CnC 3 Kane's Wrath: Steel Talons (not meta, but fun to play)
WC3: Orcs. (Watch tower Rush + Tauren Warchief)
Grey Goo: The Goo "Agents of Chaos"
Etherium: Vectide "Of course my liege."
Emperor: Battle For Dune: Atriedes "For the Duke" (Love Minos plus Atriedes Turtle)
Generals: Zero Hour: Super-Weapons General (Aurora Alpha is brutal, plus Super-Weapons 1/2 off!)
Total War, Warhammer 2: Lizardmen "The Ignorant Call them Lizardmen, the knowing call them Protectors of the World!"
Iron Harvest: Rusvelt (Sept ftw!)
Supreme Commander: Cybrans "Tip of the Spear my Boy! Tip of the Spear!"
Bonus Mention: Supremacy plus Pan-Asian Cooperative: Civilization Beyond Earth (not an RTS but still fun) Everyone gets at least 1 bonus mention.
What are your faves?