Postimage is what I've been using.


Two interfaces to the same site:

Postimage.org
http://old.postimage.org/
Postimage.io
https://postimage.io/


I've found them to work well enough for me.
(I like the "old".)


Problem with any of them, is they can just vanish, at any time.
Even postimage at one point was complaining about bandwidth & $$, but so far, they've persisted.

The already mentioned, http://imgur.com/ also seems to be popular.


Ages ago, I started with photobucket/tinypic, but today, they are simply horrible sites.


Google, various "drives", & other "big boys", I dislike.
Too many hoops to jump through, or too convoluted a process to get, use, hotlinks & whatnot.


https://en.wikipedia.org/wiki/List_of_image-sharing_websites