From my experience this problem with imgur has to do with its shitty capcha implementation. It is slow and sometimes doesn't work properly. Eg. Multiple attempts before it pops up to ask if you're a robot. Selecting No only to get the same box again repeatedly until it finally loads properly, randomly where it'll either give you a few words to type or ask you to pick images that contain xyz out of 9 pics.
I use abload.de for my bigger pics that I don't want on imgur due to compression. It is pretty simple to use but it isn't in English. Still, I was able to sign up, activate account and work everything out easily.
I don't use anything else because between abload and imgur it covers my needs and migrating my albums is a pain. Even so, consider these.
Slimg
SLiMG - Upload and Share
Imgbox
imgbox - fast, simple image host
There are actually HEAPS of decent image hosts. It helps if you know what you need in terms of size, file types and viewing preferences. Some for instance doesn't allow galleries. Others doesn't allow hot linking. Some have bandwidth or compression. Some allows for social aspects like Facebook association or comments or thumbs up/down.
