Spring is in the air, so it'll soon be the season for drinking Hefe-Weizen. Not that being out of season has ever prevented me from throwing back a few wheat beers. Anyway, time to reiterate the Weizen pecking order.
Paulaner Hefe-Weizen remains the archetype of the style, the best in the world. The deep orange color and complex, unequalled flavor set it head (sic) and shoulders above all others.
Ayinger is also excellent, brewed at a smaller brewery and available in bottles here. Deep and complex, it's a little more bland than Paulaner, but still sublime.
Franziskaner is the most widely available. You'll find this on draft a lot in blue states. It's very good, but lacks Paulaner's depth of color and presence.
Tucher is from Nuremburg, well outside of traditional Hefe-Weizen country. It's probably the least enjoyable of all the German Hefes, but the brewery gets some slack because they brew Bajuvator, my favorite doppelbock.
American hefes are usually terrible. Either the water is wrong, or the brewer doesn't do the complex decoction mash correctly. They usually have kind of a swampy flavor that would make a German engineer cry. One exception, according to Bruce, is Pyramid Hefe-Weizen from California.