Buying and Tasting Lambics

Extant Styles

Fox, or Young lambic: A plain, ~1 year old lambic. Usually a rougher tasting beer. Usually flat.
Faro: A young lambic sweetened with sugar, sometimes diluted with a weaker, more normally-fermented beer.
Gueuze: A blend of mostly (in the case of a good blender) old (2+ years old) and young lambic. The unfermented materials in the young lambic allow for carbonation making this quite a lively beer.
Fruit lambics: Made by adding fruit to casks of young lambics and fermenting for a few more months. Fruits used include raspberry, cherry, peach, grapes, black currant, and banana!

BURP Labs has a Belgian Judging guide that is very good. See also Phil Seitz' Belgian Beer Style Notes and Tim Dawson's beer style guidelines. Also the new BJCP style guide is very good.

Commercial Examples

Identifying Lambics

Don't mistake fruit beers for lambics. There are a lot of fruit beers that are not lambic (notable example: Sam Adams Cranberry Lambic). Lambics must be "spontaneously fermented," and should be from Payottenland. One set of beers that is easy to mistake for lambics is the excellent line from the Belgian brewer Leifmans (e.g. Goudenband). These are oud bruins and as such are sour and have unusual yeast flavors, and some have fruit.

Commonly Discussed Examples

Lindeman's: These lambics are by far the most easily found in the US. They are also the least traditional. They are pasteurized and sweetened at bottling, and the fruit versions seem to use some kind of fruit syrup as the flavors are strong and strange. They are reportedly blended with traditionally fermented beer to tone down the flavors that make a lambic a lambic. Recently Lindeman's has been selling a very good, traditional gueuze in the US called Cuvee Rene.
Belle Vue, Mort Subite, Timmerman's, DeTroch: Also fairly non-traditional makers. DeTroch has the patent on the banana lambic. DeTroch is also selling limited quantities of a traditional gueuze in the US.
Cantillion: A highly respected lambic brewer. Their beers tend more to the acetic (vinegar) rather than lactic sourness. They make a beer they call Rose de Gambrinus which has raspberry, cherry, and vanilla flavors. Sparsely distributed in the US.
Boon: Another respected brewer, Frank Boon started off as a blender, buying other maker's worts and doing the fermenting and blending himself. Boon's beers are probably the most accessable of the quality lambics.
Hanssens: Considered by many to blend the finest lambics, these are now being imported to the US in small quantities by B. United.

There are many other small makers and blenders but these are essentially never seen in the US.

Finding these for sale

If you don't know where to buy these beers, check out this page of importers to find the distributor in your area.