totally depends on the tunes you want....
hard to finsd have a really nice user interface for looking at tunes, which to the "novice" is quite cool. plus you can search by remixer and all sorts of stuff..... My only complaint is that they can be slow on the postage, (and it's expensive)........ If you need to call them, try calling Charman (main number), and mention Rob...... (Charman is cool as school - she's even on my xmas card list!!!)
htfr often have some tunes you will not find elsewhere in the county - so its always worth checking out to see what imports they have...
Juno offer a first class mail order tunage service, with most importantly longer and higher quality mp3s of all the tunes in their catalogue.... plus postage is really quick too..... JUST BEWARE - all prices are ex VAT!!!!
Why not check out plasticfantastic.com? real audio clips and tippety top tunes......!!
If your're into hard house, come down to chocis chewns in st annes court (i'm there most saturdays too, if not ask for peter or andreas and they will sort you out)...... Also Craig at Trax on Greek Street is perhaps the best ever record store blokie - will definitely help you develop your sound!
Reckless are pretty damn cool, but BEWARE of RIP OFF PtRICES!!!!! They tend to charge through the nose....... Excellent for 97-02 stuff at the moment (house) and some amamzing wierd trax you would never consider buying otherwise..... Tend to be a bit more "aloof" than any other shop though, so don't expect VIP Treatment....... and lets not forget the one and only XSF - the HMV of harder music.... Even if you cannot stand hard house or trance, this place is well worth a visit just for the experience!!!!!