It really depends upon what you are trying to share. You know byoac still has that file upload system in place. Imageshack is still very free and hosts images forever.... my avatar is hosted from there.
In terms of "questionable media sharing" they are all kinda junk though unless you are talking about a personal cloud that you give others access to.
Nothing nefarious.

I have a couple MAME builds with the gear shift toggle removed that used to be on Megaupload.
A few people have asked for them. I'd rather upload it once and be done with it. (some of the other sites expire in 30 days if there are no downloads)
Also have a mame.xml (v.146) file that has had all the mechanical, slots, mahjong, poker, etc removed.
I made it so it would be quicker to make changes to, but it would also be useful to newb Mala users who could just swap it in and be rid of all those games from their main gamelist.
I didn't know about any file upload system other than attaching to posts and these are too big for that. I'll have a look around.
I have skydrive from microsoft, but as far as I can tell, it reveals my name to the people I give a link to, so I don't want to post it in an open forum.
Just discovered that I also have cloud storage on Amazon, but haven't tinkered with it much yet.