Compare these graphics cards?

I'm not familiar with these, so pardon my lack of knowledge in this area.

I'm buying a new laptop, and while not primarily for gaming, I'd like to play a lot (GW2, WoW, Skyrim, Borderlands 2, etc)

I'm on a tight budget though, so I only have a few options as far as graphics cards that come with the laptops. So far, I have the choice of:

-AMD Radeon HD 7420G (with up to 2029MB total graphics memory? should I be looking for a standard amount?)

-AMD Radeon HD 7520G discrete-class graphics, up to 2029MB total memory

-AMD Radeon HD 7520G dual graphics (is this any different?)

-Intel HD Graphics 4000

-Discrete NVIDIA GeForce GT 520M (with up to 1GB dedicated DDR3 SDRAM)

-ATI Radeon HD 7670M (this is the one I wanted, but I'm not sure I can afford the laptop right now)

Thank you!