Sainsburys Be Good to Yourself Chargrilled Quarter Pounder Beef Burger (2.5 syns on red or EE).
I bought a box of four of these (£2.49 I think), and was very impressed. One was just right with my jacket potato, sweet pepper and chilli cottage cheese (Asda) and nice big side salad.
Ohh lovely, might try these. I have tried the Tesco Light Choices Quarter Pounders which are only 1.5 syns each on a red or ee day, dont know how much they are though. Thanks for the recommendation!