http://www.htfr.com - hard to find records, often a good place to look if everywhere else is sold out, and they have an excellent range of equipment. also they do self written blurbs for most of their products, which dswat boomkat and urban decay do. its not a major thing but i quite like the personal touch.
actually i would like to second
http://www.dswat.com, its run single handledly by a guy who goes by the name of parasite, a bristol based dj who also runs deathsucker records (home to aaron spectre and bong ra among others). the guy is a legend and deserves your dollars, i feel happier giving dswat my custom than some of the bigger shops. and it helps that it has a fantastic range of stuff, some really interesting gems among the catalogue.
as for real life record shops, i dont really know many. i went to nicky blackmarkets record shop in soho last week, its called bm soho and it has a decent range of dnb, house, grime/dubstep, funk and dub. had myself a great couple of hours in there and it was nice chatting to the folks who work there as they had an encylopedic knowledge of the music.
can anyone recommend any record shops in kent? i know theres a one or two kentians on this forum, i live in canterbury where theres only one proper record shop, and it sells rock..