In fact, pretty much any laptop will work.
I don't watch TV, but do use a laptop for watching DVD's, which have a higher resolution, and I use a Thinkpad 770. This has a Pentium 233 processor, though for best results it needs to have a graphics co-processor card.
If you're using a USB tuner, make sure the laptop has USB2 - otherwise you can get PCMCIA tuners.
You might also want to think about digital, as analogue is vanishing in some areas V soon.