Statler and Waldorf are definitely the ones that make me laugh the most but I've got a soft spot for Gonzo and Animal's just a very cool character. Actually all of The Electric Mayhem were pretty cool. Also Pepe (shut up he's awesome) and Fozzie whose failed attempts at making people laugh really resonate with me on a personal level. Oh and Honeydew and Beaker always gave me a bit of a giggle.
BRB, need to rewatch a bunch of muppets stuff.