I have been using Photobucket since 2004 and I had not realized how much troublesome it was than ImageShack. As a web developer I have often used Photobucket to store images thus saving bandwidth. However I did not realize that there was a bandwidth limit and most of the time my website would be in disarray.
Pros and Cons for Photobucket
1.) Images can only be uploaded if you have a user account
2.) Images get resized if they are too large
3.) Easier to understand and use
4.) Sweet interface
5.) Has a terrible bandwidth limit, replacing your pictures with their logo
Pros and Cons for ImageShack
1.) Images can be uploaded without a user account
2.) Images don’t get resized and can be viewed through a direct link
3.) ImageShack shows too many ads if you do not know how to modify the thumbnail anchors
4.) If you would not take a second look at the site you would swore it only contained ads
5.) Best of all no bandwidth limit on the images
Overall, I choose ImageShack for the only reason that it hosts the images in full sizes without any annoying adjustments.