I use Flickr and i still have photobucket (sux lately). I like IMGUR for quick upload because account,registration or log in is not needed.
You can open a thread ask this question bellow on POTN,create account, it's free; here are 1000s of pro and amateurs lurking this site daily;
http://photography-on-the.net/forum/index.php?full , go to this sub-forum ,
Presentation & Building Galleries"; maybe the best photo forum on the internet .You will find all kind of tips about gear, techniques, post processing and presentation to improve your results even for amateurs;
Over 90% are using Flickr, and laughing at photobucket, and very few Smugmug, picasa ... .