Getting killed by trees is pretty funny or seeing a 200k dps DH get killed by log trap or plants in the oasis.
Maniacs aren't funny just annoying and now there are more it seems.
Banner someone and land on a sentry is pretty funny done it 100s of times. Been in some coop groups with 3 pack and could not port in ever had to run.
Getting killed by the arcane explosion that happens when you kill an elite. Some developer is laughing his but off each time someone dies from that. Go from playing your barb or monk and play your DH you die because you forgot to move.