Just to play devil's advocate. It's because of Photoshop piracy there aren't more higher quality and cheap alternatives to Photoshop. For example, Artgem, an amazing art program (which has features even Photoshop lacks) shut up shop. I would've loved to see what that became.
We would've had programs such as the recent RealWorld Paint or Paint.net sooner and better. Photoshop is far from perfect, and is/was extortionately priced. But we missed the vast competition it would have naturally had.
As /u/Telespentry graciously mentioned, both Gimp or photoshop could do! But, you could always check out RealWorld Paint!
It has a real nice select tool. Or, at least it's better than MS paint, sorry to say.