"Goblins 3" is my favourite! Although, actually... I never played "Gobliiins 1" because the graphics are so simple to be utterly boring, and I never played "Gobliiins 4"... because I really, really dislike 3D and I think that it was a big step backwards compared to good ol' pixel art.
I've been waiting for this game, particularly "niveau psychédélique" sounded very tempting to me as a fan of psychedelic theory and psychedelic rock since an early age...