If you're going for something special and want a vintage champagne, go for one from 1990 - one of the 18 most fabulous vintages of the century and the best one to drink at the millennium. There are about 15 of the 1990s still available, the best one being a Billecart-Salmon cuvee. If you can't stretch to this, don't despair; the Waitrose Cuvee 2000, at pounds 25, is a 1990 vintage and definitely the best supermarket champagne.
If you're looking at a champagne you don't recognise, a good tip is to look at the bottom of the label for two small letters. If you see the letters NM, the champagne was produced by a house, such as Moet for example. If the letters are RM your champagne was produced by a small grower; CM means the champagne is from a co- operative - it may be good value but remember that no top quality champagnes are made by co-operatives.
If it's cheap fizz you're after, there are hundreds of supermarket champagnes for under pounds 10. Marks & Spencer and Waitrose are probably your best bet; they've been choosing champagnes for a long time and do it well.
You don't have to drink champagne at all. Cheaper and equally fizzy is cava, although the grapes used are grossly inferior to those used for champagne. If you're after something sweet, go for a good asti rather than a champagne demi sec (semi-sweet), which will cost you four times as much.
You should really buy champagne to drink, not to keep, although there will probably be bargains to be had in January for the next new year - though I suspect, by then, we'll all have had far too many bad headaches to think about that.
Tom Stevenson is the author of `Millennium Champagne and Sparkling Wine Guide', published by Dorling Kindersley, pounds 9.99Reuse content