I would say soundcloud but sometimes does fuck you over with copyright shit so when that happens I turn to mixcloud, apart from those 2 I don't use any others
My work's web access lacks any kind of logic.
They've blocked SC and Mixcloud, but sites like vevo, facebook and youtube are ok.
Anything with the term proxy associated is blocked too.
dnbshare is fine tho.
deadaelus introduced me to Mixcrate, http://www.mixcrate.com/deadaelus/low-temp-9184501
Looks pretty good but misses some of the features I liked about soundcloud. There is a download but you have to be signed up for it.
Pretty decent! I was recommended it by someone on here when looking for somewhere I could upload a 6 hour mix and that seemed to be the only place for it. I use soundcloud though but it's a good alternative.