Portobello (I love Portobello and the vintage shops round there........but get there early on a Saturday and be done by midday cos it's tourist trap central after midday)
Spitalfields (it's not predominantly clothes and there's a lot of antiques, food etc but the clothes/jewellery they do have is very good)
Camden (the actual outdoor market is tat tourist city imo - however there are some good stalls in the Camden Lock, Camden Canal, Stables markets - if you're coming from Camden Town station walk up towards Chalk Farm tube past the outdoor market and then you'll see the other markets)
