http://www.leconcepts.com/rxr/pirxer.htm
Pioneer VSX-C402 for £199.
Two friends of mine have the older VSX-C301 receiver and it gives a very good account of itself.
It's well worth noting that at the £200 mark you
will get better sound quality from a full-size unit such as the
VSX-D514 (also £199) rather than a slimline one. You'll also get far more inputs and the all-important six channel input for SACD and DVD-Audio, which you won't get on the slim receivers.
As an aside, if you can afford £50 extra, I can't emphasise enough how GOOD Pioneer's Automatic MCACC speaker setup system is. The cheapest model featuring it is the
VSX-D814, which you can see on that page for £249. It will do a very good job of getting the best out of whatever speakers you have.