How much do you want to spend?
2 years ago I got a Dell Studio 15, 256MB ATI Radeon HD Mobility 3450, 2GB Ram and a 2GHz Core 2 Duo, I forget exactly how much I paid I think around just over £600 thanks to some Dell offer. Been perfectly fine for me, used it for programming, movies, TV (either through iPlayer type thing, or via a USB TV Tuner) and games (all the games I tried at least worked, might have struggled with some of the more demanding ones).
You should be able to do a lot better with £600 now (there are often offers on around this time), although Id say the only place it will make any difference to you will be gaming (all the school level programming I have ever seen isn't even worth factoring in, you could do it on a 500Mhz machine and hardly notice the difference in compile times and your programs speed). I just looked and the basic model (£777 normally) now has a "1GB ATI Mobility Radeon™ HD5470 Graphics Card". To give you an idea mine got a G3D rating from passmark of 126, and the HD5470 got 310, with the £962 model getting 606 with a HD5650.
That is still pretty poor compared to a desktop however (the £130 HD5770 I have got 1567 and can just about play most games I have on very high/max on a 1600x900 display).