Does "fun defense" rule out "really sound defense?" For example, you could play gambit lines with Black that are not so terrific with best play by White, but are still a lot of fun to play, depending on your temperament: a) Latvian Gambit (1.e4 e5 2.Nf3 f5?!), b) Elephant Gambit (1.e4 e5 2.Nf3 d5?!), or the c) the Borg or Macho Grob (1.e4 g5?!).
They can all be fun, but are almost certainly not sustainable repertoire tools for aspiring players. Up a notch on the list might be the Scandinavian, the Alekhine, and the Modern. In any case, "fun" is defined by the practitioner, I'm guessing.
Im going to play the birds, dutch (leningrad)...but what is a fun defense to e4? Im trying to avoid the sicillian, but I might end up playing it if there are no other viable options. Thanks guys/gals.