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.
Goblins because they are funny, hydras because they are cool 😎
Cephalids! Don’t even know where this came from but at some point I got the idea to make a deck around Aboshan so I ended up going full cephalid tribal and while it’s not very good I love it anyway.
I love Elves. Just splurge them out on the board and give them all +20/+20. Sadly they don’t work well in Modern anymore. I also cut Natural Order and Craterhoof from my Commander Elves deck since it was too oppressive.
I really like playing Knights, the entirety of the lore in the game around them is really fun too. Other than that I think birds or 1/1 flyers tribal is fun, as well as defender tribal with Arcades as the commander.
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 had a good life gain angels deck before the last rotation that i really enjoyed
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.