Boheme 1795 Pilsen Czech lager in 500ml bottles, currently £1.20 a bottle, but the yellow shelf-edge ticket said £1.20 each or 3 for £2.00, which I reckon is an ace deal as it costs less to to buy three bottles than it does to buy two!
Works out less than 67p per bottle or £1.33/litre.
And the beer tastes ok too!
I've seen this in several Tesco stores so I'd say it's a nationwide offer. The shelf-edge ticket stated 01/02/2011 as the deal expiry date.