where farnell win vs rapid is every time I've placed an order...they've done free delivery (whereas Rapid charge 3 or 4 quid *unless* you order more than £30's worth of kit I think). Rapid are normally cheaper, but their range is much much less.

Maplin are (by & large) expensive, but useful if you've one nearby & only need one or two Bits & bobs.

Then there's the smaller outlets (handy for the more scarce stuff). i rather have a soft spot for cricklewood electronics.

Finally don't forget the states (especially if the pound holds its recent footing)....Digikey are often quite cheap & deliver free if you place an order more than £50 (thye pay the import duty, but you'll have to pick up the tab for the 15% VAT)