For premium service, I have been happy with Fileserve. Filesmonster is okay speedwise, but I don't like their daily download limit, so I'm not sure if I will bother renewing next month when my 90 day subscription is up.
As a free user, Megaupload is great, as is Mediafire (at least using firefox with adblocking--I used it once with IE, and it kept trying to load ad windows). I always used to hate rapidshare, but just last week I tried it out with jdownloader, and was pleasantly surprised that there was no waiting between downloads.
I loathe Oron.
Edited to add: Goodbye Fileserve and Megaupload!