Help me pick please

[sakurakana1003]

I'm buying a laptop, so far I've been able to fit these into my budget, but I'm pretty confused when it comes to laptop graphic chips. Out of all these choices, which one is the best for gaming?

ATI Mobility X1400
ATI Mobility X700
ATI Mobility X1600
nVidia 7400 Go
nVidia 7600 Go

Help please~