You see vintages talked about in wine circles; you see snobs argue over whether the '97 is better than the '96, and you wonder if any of it actually matters.

Many things influence the quality of a vintage, but it's mostly the weather. Rain around harvest is disasterous as the extra water causes the grapes to swell and become weak and diluted. Dry weather is generally good, as it makes the fruit more concentrated (at the cost of lower yields, which are also good for quality). Rough starts (such as a cold spring) can reduce the yield. These things seem to have a perceptible influence on overall quality, although you'd have to drink a lot of wine to be able to make general pronouncements about a year.

Vintages matter more in some places than others. The quality of Burgundy is highly dependent on the (very fickle) weather, as is the quality of Bordeaux. The Germans live in perpetual fear of freak cold at strange times. The weather in Australia is so consistent that vintage barely matters. The weather in California is mostly consistent, so vintages are largely for the snob. If you aren't inclined to memorize charts, focus mostly on Bordeaux and Burgundy, where it actually matters. Remember that 2000, 1997, and 1990 were great years, while the rest of the 90's were bad in Bordeaux. In Burgundy, 2001, 1999, 1996, 1993, and 1990 were good, and the rest were bad. In Germany, they've had a string of great vintages starting in the mid-90's, and 2001 is the most talked about year in a generation.

These vintage charts are compiled from reading a variety of the usual wine publications for what they thought of the year. I don't drink nearly enough wine to be able to make general statements about the quality of any specific vintage, so I cannot personally vouch for most of this information.

Bordeaux

2001
not too bad
2000
superb, will be remembered
1999
eh, whatever
1998
pretty decent
1997
great year
1996
not so interesting
1995
decent
1994
very mediocre
1993
very mediocre
1992
bad
1991
bad
1990
awesome year

Burgundy

2002
excellent year
2001
strange and uneven
2000
uneven
1999
pretty good year
1998
not bad
1997
mediocre
1996
very good year
1995
not too bad
1994
not good
1993
very good
1992
bad
1991
uneven at best
1990
Godlike

California Cabernet and Merlot

2001
Godlike; classic year
2000
somewhat uneven
1999
excellent
1998
uneven
1997
Awesome
1996
Excellent
1995
Very good
1994
Excellent
1993
Decent
1992
good
1991
Excellent
1990
Excellent

German Riesling

2001
Godlike; best of this generation
2000
mediocre
1999
very good
1998
very good
1997
very good
1996
excellent
1995
very good
1994
good
1993
very good
1992
uneven
1991
uneven
1990
awesome

Vintage Port

Remember that they only bother to make vintage port on the good years, so it tends to be good in general.

1997
Awesome
1995
Very good
1994
Godlike
1992
Excellent
1991
Very good
1987
good
1985
really good
1983
really good
1980
good
1978
good
1977
Godlike
1975
possible mistake
1970
awesome