Beasts
Celestials
Fey
Fiends
Giants
Humanoid (may need to be broken into multiple competitions and then a runoff)
Monstrosity
Ooze
Undead
I don't think have been done yet.
Some haven't, some have; see list of previous threads. (Link in the OP.)
Best Named NPCs In An Adventure
Give Meepo his day in the sun.