8000 Reddit comments could take me a while to go through:

http://reddit.com/r/AskReddit/comments/1qg0ly/what_gif_reduces_you_to_hysterical_laughter_every/

The double bucket man, everytime

http://i.imgur.com/xIolo.gif

Kid on a bike, every time.

Had not seen double bucket guy yet. Read the accompanying article - the blue light folks are crazy: 

Migalka owners are blamed for adding to Russia's horrific death toll on the roads - 95 people are killed in road accidents every day in Russia and 700 more are injured.

The gif without context is funny, but that is sad.