The medium in which the masses are exposed to the most and most greatly variegated experimental film making is definitely in music videos. Gondry and Jonze may be some of the most famous experimental music video directors but many thrive today. One of my favorite animators is SO-ME. He's the artistic director of Ed Banger Records, a Parisian record label, and has a very unique animation style. Justice's "DANCE" had a long run on MTV here in the states and was a club anthem, the success largely in part to SO-ME's hand drawn animation on T-Shirts as the musicians walked through the video. Some other works of his I enjoy particularly are Kid Cudi's "Day N' Nite" and most recently, a French electropop guy, BreakBot's "Baby I'm Yours".
I'd love to animate emulating his style.
IAN