I used to use photobucket, but I found that alot of files were re-sized, and it often ran out of bandwidth, or was down, and then I reached the limit of photo's they would let you upload.
So I now use
http://imageshack.us
There is a size limit, but I havent tried to upload anything that big yet... I figure that if its to big for them, it will be to big for people who want to view it.