I'm pretty annoyed at all these websites in that they just pester the heck out of you to get a freakin' premium account!! Stupid 30 seconds download tickets, 1 download at a time, no resume support and what not!!
But still, I think Rapidshare wins the cake for me, just because of the vast amount of content that one can find in it, and because I can easily search that content using RapidLibrary
I mainly use megaupload as it is only one of the few file hosting services I am familiar with. I don't really use Rapidshare, as I have found it to be a rather irritating experience, considering the restraints put in place.