Get this months ELLE magazine for £3.90 and get a free Soap and Glory mascara worth a tenner. I've just put it on and it's really good. Rivals my Bodyshop one which was about £14!
Morrisons - Ryvita (different varieties..don't remember all but it included cracked pepper and fruit crunch) for £1. Philadelphia (300g) still on offer at 99p. Bought the garlic and herb, yum!
Iceland - Crosse and blackwell pasta n sauce 2 for £1
Go wherever they are on offer, that's what I do as they're pretty expensive everywhere full price. At the moment you can get them 10 for 3 at Sainsburys.
Look on mysupermarket for the best prices or the 'where the bargains are at' thread on here.