I prefer Facebook and Deviant Art myself, along with Furaffinity. They seem to have the highest level of actual traffic out of the mentioned options, for me at least. Furaffinity is probably the best in terms of responses per post, and seems to have a fairly positive, helpful community. I do have accounts on Weasyl, and Reddit. Also tried out OurArtCorner, Paigee, Wysp, e926, and Tumblr, but none of these worked out well for me.
OurArtCorner is kind of exclusive, a bit messy in terms of design, and requires giving reviews and ratings in order to post content.
Paigee's image size limit is very small, - not good for detailed pictures.
Wysp, kind of the same story as Paigee.
e926 is basically just a moderately family-friendly filter on a porn site - enough said.
Tumblr got me almost no views or responses at all, and is a bit too ADD for a slow-paced person like myself. xD
Weasyl has an awesome platform and I would love to make it my home-base for that reason alone, but there's so little activity that passes by my work there.
Facebook and DA are nice for their platforms too, especially if you have friends or relatives who like your art page and share things from it once in awhile. Buying ads is also easy, and I've been able to find a target audience for some of my work, which was really helpful in getting the most out of the money spent on advertising.