I use a combination of programs. Generally I use Irfanview to review my photos, but any serious work I do in Photoshop Elements (which I think you can still get with a one-time purchase, rather than a subscription; it's also much much cheaper than the full Photoshop Suite).
Paint.NET is also a good free program that has basic layering abilities like Photoshop and a much easier learning curve than something like GIMP. There's also a free plugin available so you can open Photoshop files in Paint.NET, although I don't think you can save them.
