Though no longer brewing, this contract brewed dark beer is a winner nonetheless. Have one while in Bayreuth by all means.
Krug Lagerbier is one of the finest Kellerbiers in Franconia. It is unfortunately not being brewed at this time and hopefully will return soon.
One of the most pleasantly surprising bock finds I've stumbled across, Hübner's bock is a dry fruity wonder.
Erlangen's big brewery is a surprising winner with great food and a large portfolio of well-crafted beer.
Mahrsbräu makes one amazing bock and there's no better place to drink it then at their atmospheric brewpub in Bamberg.
Kraus Hirschentrunk is a great introduction to Rauchbier with a light but definite smokiness to balance out the malty but dry palate.
Bavaria has over 400 breweries and getting to them is easy even with public transportation. This should help you find your way there.
Trains are a great option to get around Bavaria, especially when traveling to breweries. This should help you get on track.
Sometimes there's no bus to a small village with a great brewery but there might be a bus. How to catch that bus right here.
Driving in Bavaria is a great way to get to out of the way places and once out of big towns, is quite pleasant.