I worked in the printing industry for eighteen years and owned a service bureau for six of those years. So, you know I'm going to stand by Adobe any day of the week. However, if price is a concern and you don't mind the lack of CMYK support, check out
The Gimp. If you're doing stuff for home and/or Web you don't need CMYK anyway. This is GNU General Public License software that IMHO is outrageous for free.
Note: To use The Gimp you must first install GTK+ Runtime Environment 2.4.14. Then install The Gimp.
I use this on XP and it works great!