I, too, have to recommend the Model M. I bought one about four years ago after having enough of the spongy rubbish that masquerades as keyboards these days.
Not cheap, especially when you get clobbered with VAT and import duty - you have to order them from the US of A.
I suppose you could try and get an "original" on EBay but, if you are a serious computer user, getting the best keyboard that you can is an investment in your health and well-being as much as looking cool on your desk.
Get one... you know you want to
UPDATE - you can get these in the UK from http://www.keyboardco.com/
http://www.keyboardco.com/keyboard/orig ... ck-usb.asp
£94.80 including VAT.
Not affiliated - just noticed this and thought I'd share.