The UL series is fine if you need portability and longer battery life. However, since they all use low voltage processors (they have pretty low clock speeds) and most use integrated graphics, none of them are going to be that good for gaming.
What card is in your current laptop? How much are you looking to spend?
Basically, I believe the answer is no. Maybe if you used low resolution and low settings, but even then it won't be a very enjoyable experience. I'd say a GT 230/240M from NV and an HD 4670 from ATI are about the lowest you want to look for if you want to play games decently.