The best compression possible

Hi All
Im looking for a codec giving med the best compression possible, and by that i do not mean a lossless codec, but a codec that gives me the smallest possible filesize. I will be capturing a desktop at 320x240@15fps and no audio. It is ok that I loose some quality but the details still have to be some what visible.
Any suggestions?

hm...interesting

H.264
There’s a lot of tools for that. (Relatively) easy to use would be RipBot264. A bit more complicated, but with more options, is megui.