Adobe's Photoshop LE (Limited Edition) is pretty good for web graphics. It has the same look & feel as Photoshop, but is only around $100.LE isn't as robust as its big brother, but what can we expect at a sixth of the price!
Some LE limitations are:
LE only uses RGB color. This meanse that you can't use CMYK or reliably create anything that will be professionally printed. But if you're using it only for web graphics, RGB is pretty much all you need.
LE doesn't have a History option. This option lets you revert to previous file "states." If you made a mistake a few steps back, you can essentially go back and unapply the changes.
LE doesn't allow you to create macros. This capability will allow you to save time on repetitive formatting issues.
LE does not support editable type, which is a major time saver. Once you enter some text, it's rasterized and set in stone. A nice feature of the new Paint Shop Pro is that it supports editable type.
LE does not support vector images. Once again, it depends on how much you use these types of images, which are frequently used in print media. PSP supports vector graphics to a certain extent, though not as well as Adobe Illustrator or Photoshop.
Photoshop LE offers a lot of bang for the buck. I'd rank on the same level as Paint Shop Pro. Each program does certain things better than the other, so it's your choice. I will say that LE's interface will get you up to speed on Photoshop and acts as a very effecive stepping stone to the full product, should you ever decide to go there.