The old and shareware (30 day) version of Paint Shop Pro (v.4) is still very good ->
http://www.pagetutor.com/downloads/psp412.html
I'm not sure, but I hear that after the 30 day trial (instead of disabling the program) it just nags you to register every time you startup the app. So if you can stand unclicking that nag screen off everytime you want to use it, then I guess it's alright. But like I said, I'm not so sure about this as I haven't tried the freeware version and I had the registered version a long time ago but stopped using it when I got Photoshop.