I strongly recommend Linksys (by Cisco), I have had 3 different models over the last 10 years and havent had a problem with any of them, they are fantastic. If you want a direct replacement of what you have probably got atm you would be looking at this one:
http://www.dabs.com/products/linksys...22-50468&src=3
If you want one which is going to last you a while with 802.11n, dual band and gigabit ports you need to be looking at this one. It is well worth the extra £13 you are looking to pay:
http://www.dabs.com/products/linksys...22-50468&src=3