Keyboards are so much personal preference that it's not really possible for anyone to recommend one to someone else.
Generally Microsoft and logitec are good brands but your best bet is to take a trip to somewhere like PCworld that will have a decent amount on display so you can find one you like the feel of.
I agree with Chuck, personal preference is everything.
If there are independent shops or a Maplin shop near you go in and have a go. Problem I find with our PC World is limited choice.
I have never found any that I like better than my prehistoric(15 years and counting) one made by Cherry.