Can be any format.
For Commander decks, I have at least 5 Dragon tribal decks already and am planning to try to build a dragon tribal deck out of every possible multi-color combination plus mono-red eventually. But Slivers and Eldrazi are up there too as two of my favorite tribes to build around.
I had a good life gain angels deck before the last rotation that i really enjoyed
My favorite tribal decks before I took my EDH decks apart were vampires and dragons. Vampires for the aesthetic + flavor and having enough to go deep on the tribal theme. Dragons because who doesn’t want to whirlwind slam a deck full of fatties?
I used to love Vampires in Ixalan Standard when Arena was new.
So I got a soft spot for those
Dinosaurs, probably. I have a Gishath deck in paper and on arena and they’re super fun.
I’m stuck on Demons. It’s challenging to keep the mana curve to a manageable level but otherwise finding it fun to play especially after the Warhammer 40k set added some additional choices.