Germany

Known best for some ill-famed sugar-laced [Mosel] wines, Germany is still fighting a bit of an uphill battle in the United States to regain a reputation as a source of fine wine. However, if you care to look closely, you'll see that there are many diverse winemaking regions throughout the country and in most of them it is quite easy to find a good solid bottle of white wine. Germany is not particularly known as a red wine country although due to some recent efforts to grow good quality red especially in the south-east corner ([Baden] and [Pfalz]) bordering the French region of [Alsace], there are some up and coming red wines.

There are 13 different officially recognized wine growing regions in Germany (see below), each of which has a controlled list of grapes that are allowed in the region. Germany has adopted a quality control system very similar to the French [AOC] or "appellation d'origine contrôllée". It knows four general categories of wine that are exact equivalents of the categories defined by the European Union and present in all major European wine countries:

[Tafelwein] is similar to the French "vin de table" or the Spanish "vino de mesa" in the sense that it does not have any constraints on grape origin, blending or wine making. However, like in other countries some wine makers choose the category because it gives them the freedom to produce the wine they want. Therefore you will see the occasional pricey and good table wine despite the fact that it is technically the lowest step in the quality ladder.
[Landwein] needs to adhere to slightly more stringent controls of origin. For example its grapes have to be grown in the region mentioned on the label.
[Qualitätswein bestimmter Anbaugebiete] (aka "QbA") guarantees that all the grapes used for the wine have been grown in one of Germany's designated wine growing areas and has been made in accordance with the local traditions.
[Qualitätswein mit Prädikat] (aka "QmP") follows the same rules as QbA wine and in addition has to go through testing that awards it the attributes for alcohol content and sweetness - as long as the producer can prove that getting to the extra alcohol or sweetness level did not violate any of the wine making rules.
In addition, wines classified as QmP are rated for factors that influence alcohol content and sweetness. The different categories are:

[Kabinett] for wines with low alcohol content. Almost always a very dry wine.
[Spätlese] for grapes that were harvested past the traditional harvest season to guarantee a fuller ripening cycle and higher content of grape sugar. As a result, the wines tend to have higher alcohol content than Kabinett wines. Some Spätlese wines gained a reputation of being too sweet, but this is a choice by the vintner to stop fermentation before the grape sugar has turned into alcohol. Look for the word "trocken" on the label, if you prefer dry wines.
[Auslese] describes a process of selecting extra ripe bunches of grapes from the harvest and making them into a separate higher-rated wine.
[Beerenauslese] literally describes the same process applied to individual grapes rather than bunches. It typically yields a wine that is high in alcohol and sweet due to the grapes being overripe. Most Beerenauslese wines are dessert wines and lend themselves well to storage.
[Eiswein] is made from grapes harvested after the first frost (and often while frozen). It typically yields a wine similar to Beerenauslese, but is riskier for the vineyard since the frost needs to hit the grapes at just the right time and intensity - if it takes too long, the grapes will no longer yield a useful wine, and if the frost is too intense, the harvest will be ruined. Therefore, most Eiswein producing vineyards will not have one for every vintage (if they do, I'd be suspicious ).
[Trockenbeerenauslese] is made like Beerenauslese but the grapes are dried slightly before being pressed and fermented. They will therefore have an even higher percentage of sugar per liter of must and thus produce a wine that is even higher in alcohol and sugar content. The method of drying the grapes is similar to the one used for [Amarone] wines in northern Italy.
The officially recognized wine growing regions in Germany are:

[Ahr]
[Baden]

Franken


[Hessische Bergstrasse]
[Mittelrhein]
[Mosel-Saar-Ruwer] ("Mosel")
[Nahe]
[Pfalz]
[Rheingau]
[Rheinhessen]
[Saale-Unstrut]
[Sachsen]
[Württemberg]
[Links]
Wine Page of the German Embassy in London