are fast and usually have good stuff (I bought a nice 1.6 slimHD from them)
but staaaay awaaaay from http://www.amigastuff.co.uk
! their joysticks are rubbish and they forget your order
there is also http://www.eyetech.co.uk
but they are a bit expensive and the site is confusing...
I recommend http://www.ebay.co.uk
people are usually nice there (or I've been lucky sofar)
Wasn't there a thread about this in Amiga Website reviews btw? it probably has more stuff listed
edit: ack! ant512 beat me to it!