The question you need to ask yourself is "what do I need a graphics app for?".
For anyone who just needs to create the odd Sig file or correct a few digital photos then one of the freeware options is fine - Gimp Paint.Net or even Picassa.
If you are serious about graphics work then Photoshop is a really the only option - Photoshop skills are a salable skill in the employment market
, and is so well supported online with tips and tutorials that it can be easier to learn than simpler options.
One thing to consider is that with the release of CS4 the real world price of CS3 has dropped so may be a better economic option for the beginner than CS4. The same would apply to Photoshop Elements if you do not require some of the more professional functionality of CS4
The purchase of a graphics application is something that should be given a lot of thought as people tend to stay with the package they are used to more that with any other type of application.