In addition to the sites already recommended, I can add couple other ones that I am considering myself. 1. fotki.com - They've been around for several years, and I know many people who have been using them. I haven't seen bad connection to them. cons: recently increased price for the premium account ($50), and absence of indexing the albums (i.e. assigning several keywords to each album, and then creating "virtual" albums based on a separate keyword).
2. Just a few days ago a friend of mine mentioned http://www.smugmug.com/ I haven't checked all details yet, but it seems to allow indexing and more. Hope that helps, Igor