I like imgur. They've changed their setup a little, but once you learn the change it's still pretty easy.
1. Go to their website
2. Post the image you want to share.
3. Right click the image and select "open in new tab"
4. Copy the url.
5. When putting it here on the arena, put it between [ img ] [ /img ] tags (without the spaces).
I don't think you can crop or resize on imgur like you could on pb, though, so make sure your stuff is no more than 600 pixels wide so it will work properly.
I hope this helps.