Lauren's exactly on point: it just depends on what you want to do.
I chose Photoshop full-version because I'm anal and like to make everything myself (and I mean everything! I upholstered my own couch, grind my own wheat, grow a garden, sew clothes, we build furniture, and the list goes on...it's a sickness, really
I knew I'd never grow out of PS, it's the professional standard. So given my tendencies, I don't have a problem with a lot of work learning something new.
But the simpler programs, like HP Creative Assistant, for example, is strictly an assembly program. You don't make your own elements, you use premade and assemble them creatively with that software.
What do YOU want to do? How much time do you have?