image shack is great! I have two photobucket accounts but I prefer the anonymous ways image shack provides their URLs for images. they allow 1024kb files, which is wonderful for those screenshot threads.
give them a try.
If it is just for hot-linking and forum posts, then ImageShack is pretty sweet, hardly beatable save for personal webspace if you prefer that. If you are trying to store and show galleries, well then Flickr isn't bad, but I never really liked it. I haven't used too many others.