First of all, youtube is crap, and people like making videos.

Shoot in high definition. It seems to work.
Wmv is probably better than mp4 but there is not a lot in it.
Use the best video encding setting
Use 30 frames per second
Use a size of at least 320 by 240
Aim for a frame rate of about 1,000,000
increase these last two settings by a factor of about two for best performance up to a maximum memory of 100 megabytes.

Alternatively use
vimeo.com


Tim