ibook or powerbook?

I'm thinking about switching over to a MAC. I want to purchase a used notebook and was wondering which would be my best bet; a power book or and i book?
I already have a notebook and was hoping to only spend around 500 dollars give or take for right now. (Planning on using for surfing, email and light gaming.)

I would go with the most powerful Mac you can buy with the money you have; it will last longer. I know the Powerbook is the higher end notebook vs. the iBook but you don't mention specs of either so it's hard to say. At this point though, I would seriously think hard about buying a non Intel Mac.