As far as amateur work, xhamster has been popular for a long time now and has developed a deep library of content in a variety of categories, I’d say even more than Pornhub. In recent years it pornstar content has increased significantly and now hosts a lot of older content from bigger studios.

Xvideos and its affiliate xnxx, is essentially the Library of Dongress and hosts or has hosted almost every porn video in existence. The platform makes it easily shared, but its popularity means a LOT of videos get deleted, then reposted by users so finding an old favorite can be like searching for a needle in a haystack. The biggest drawback is the lack of true HD playback.

YouPorn and Redtube are both more medium sized sites with a fair amount of full-length videos, but Redtube is also subject to strict copyright claims and a lot of videos are stripped out pretty often.

Spankbang has been storming up in popularity, with an ever increasing library of full-length pornstar content, while also including work from camgirls and full HD playback on some videos.

Beeg, a personal favorite, started as a more bloglike format, with minimal frills, but TONS of full-length videos in crisp HD and a very smooth native site player. Its recently grown to a point that its admins are introducing suggested search (by tags or names) and even performer profiles. I highly recommend it.