I use Photobucket. Easy to copy the links. They did hijack all my pics a few years ago and try to charge a boat load to use them. The went back to being free with a watermark.
Photo from Flickr - On Flickr hit Share on the pic then hit BB code, copy and paste the link.
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Trenton Sain, on Flickr
Photo from Photobucket. From the same rough day. Photo bucket tries to get you to buy something twice before you get to your pics.
I may start using Flickr