Gewürztraminer is a
superior white wine. Yellowish in color, it's sweet without being
cloying. It has a spicy
nose (the word means something similar to "spice wine") and a spicy, fruity flavor, with a distinct aftertaste. Pineapple, apricot, cloves, pear, and citrus are frequently cited -- my favorite Gewurtzes have strong pear, citrus, and clove scents and flavors.
Although imported Gewurtzes are prized, in the U.S. several winemakers have well-respected domestic lines. As with any wine, avoid the cheaper varieties -- I bought a bottle of Sutter Home and decided that I would have been wiser to spend my four bucks on Fresca and Lavoris.
Although you can spend as much as you want to, a bottle in the eleven dollar range is your best bet for after dinner. Turning Leaf's offering is quite reasonable and tasty, as are Kendall-Jackson,Columbia Crest, and Fetzer. Gewurtz is a dessert wine, and its fruit flavors go well with fresh fruit or a compote. (Yes, it's also said it goes well with cheese. What doesn't?) It is highly recommended for spicy asian dishes, and I vouch for it with pad thai and Schechwan vegetable and/or tofu dishes.
The grapes themselves are relatives of the Muscat, a sweet and flavorful green seeded grape (frequently used as root stock for Thompson Seedless. In Europe, Gewurtz grapes are grown primarily in the Alsace (and tiefling informs me that northeast France produces excellent Gewurtzes). In the U.S. they are found on the Left Coast.
Bonus information!
hopthrisC says the grape is listed as red, although sie's never seen a red one, and is a cool-climate grape, growing in France, Germany, Austria, Hungary and down to Rumania, as well as New Zealand. Sie also says that "Traminer" is a more common short name for this wine. I'm not familiar with that usage. Then again, in Minnesota it seems like the only alcoholic beverages are "beer" and "not-beer" ;). And, "the few bottles every year my granddad used to make back in the days never really got old ;-)"
hopthrisC and Albert Herring identify the second half of the name as coming from village "Tramin" in Southern Tyrol (now part of Italy), italian name "Temeno". Albert also points out that Luxembourg has Gewurtz vinyards.
I would like to thank everyone who helped me improve this writeup, including everyone who pointed out that it really needed an ümlaut. As far as the superfluous "t" in the short form, it's there for pronunciation.