I think there are several things to consider with this question.

The first is do you have any ambitions to use either of these programs as a professional tool? If so, I would strongly suggest Photoshop as it is the industry standard. My reason is that the vast majority of professional studios you will ever walk into are using Photoshop. If you expect to find a position in this industry knowing Photoshop is a basic requirement.

Second is the interoperability of Photoshop with other Adobe programs such as Illustrator, InDesign, Pagemaker, etc. Again these are important consideratioons if you are planning to do this professionally.

Ultimately the choice is up to you... They are both good programs, and in the end either one will become a valuable tool if you learn all the ins, and outs.