Xvideos and xnxx - videos load quite quickly and are generally glitch free.
nuvid.com
Youjizz is a good one too!
tubegals.com
tubegalore.com
tiavastube.com
Worth installing adblock plus (if you use firefox) regardless of which sites you use. In fact I have it on all my machines anyway, not just for porn!
Zoig.com
Xhamster.com
fantastii.cc
vidsvidsvids.com - for videos