There is a good sticky on this forum for a comparison of flavors, resistances, AA% and styles.
Midwest supplies closed their pages that I usually reference. Good thing google caches the internet.
Tettnang : 4.0-5.0% AA. Grows well in moderate climates, suffers a little in hot climates. Tettnang is a Noble hops. It is herbal, slightly woody, slightly spicy. Tettnang is used in German, Bohemium and American Lagers.
Willamette: Grows well in all climates. A U.S. grown cousin of Fuggle. It is very similar to Fuggle, but it does have a more fruity and floral note. It is earthy, fruity, slightly woody and slightly floral. 4.0-6.0% AA.
Cascade: Grows well in all climates. Susceptible to aphids. Cascade is the traditional American Ale aroma/flora hops. It adds a citrusy, grapefruit character even if it is used as a bittering hops. 4.5 - 7.0% AA.
Northern Brewer: Grows well in temperate climates. Suffers a little in hot climates. This hop has a very woody, earthy and slightly fruity aroma/ flavor. It is a noticeable hops in most beers. 8.0-10.0% AA.
Hallertau: Grows well in mild, moist climates. Suffers a little in dry, hot climates. A very traditional German hop variety. Plants can produce abundant hops the first year!