It really depends on what exactly you do with photography. If you're an advanced user that needs an efficient and powerful workflow, PhotoShop CS5 is the way to go. If you're new to photography or you just do it as a hobby, PhotoShop Elements is a great program. And Lightroom is really just for cataloging images, but it does have fairly powerful editing tools as well. Just keep in mind that if you're really new to photo editing, learning how to maximize CS5 is going to be a lot of learning. Elements is more user friendly, based on what I've seen of it.