Hi, sucks about your pc - when they dropped the prices they dropped the quality as well. 15 years ago a pc could run to over 1500 pounds, but it was built like a tank and lasted forever.
The answer to your question is simply that it depends - mostly on what you use your computer for and your budget, although there are some other factors.
Money no object I'd go for one of the new Apple Macbooks or a new Dell Alienware laptop.
Below that there's a huge number of brands, models, prices, sizes etc etc...
I think nowadays at the very least you should aim for something with an i3/i5/i7 processor, 4gb ram, 500gb hard drive, 17" screen and after that as much extra stuff as you can afford I suppose.
Hope that gets you started on your search! Good luck