German Riesling comes in all levels of sweetness from bone dry to very sweet dessert wines. Although the most common style is still moderately sweet, that is starting to change as the current vogue in Germany is for dry and minerally wines. The label will often offer clues to sweetness: trocken or halbtrocken means dry while spatlese or auslese will almost always be quite sweet. Kabinett will be somewhere in between.
French Riesling tends to be drier, richer, and fuller-bodied with less apparent acidity and typically a pronounced minerality.
California Riesling was traditionally made to be simple, sweet, and inexpensive. Although some wineries are making drier more elegant examples, the majority of American Riesling is still quite sweet and straightforward.
New Zealand and Australia are having success producing drier, more elegant citrusy examples from cooler-climate vineyards.