I've gone through 3 kindle covers in the past 7 months... The one i keep going back too is this cheap $16US cover from boxwave.
http://www.boxwave.com/products/sien...-case_3469.htm
(they have a few different colors)
It holds the kindle tight, It’s got nice padding to protect the kindle in travel... but most of all i like how it feels in my hand.
Everybody that i know with Kindle has bought one after holding mine.
If you can find it in the UK you may want to give it a try.
~Brian