I recently downloaded a free photo editor, Photoscape. It was a bit similar to Picasa, but had lots more editing stuffs (which takes some getting used to, lol). It reminded me of Gimp (another free photo editor), but less complicated. Till now am still getting the hang of it.
But honestly, I prefer photoshop. I know, it's because I have used that for ages and so am comfortable with it. Still, it's a good thing to learn something different every now and then. :)