I have to second every recommendation so far.
Pretty much any where in Belgium: Brussels, Brugges, Ghent (then make trip to Westvlettern if you desire); 't IJ, & Gollem in Amsterdam are two of my favorite places (ESPECIALLY 't IJ; and it's very reasonably priced) -I regret not making the trip to De Molen when in Amsterdam but I did try quite a few of their beers (Beer Temple didn't exist then as far as I know.).
While I agree with Prague (and like the other cities on the list, it's an incredibly beautiful and fun city even if you don't like beer), if you're going to include Prague in the list I think you have to open up most of the major traditional brewing centers in Germany, too. Munich is great fun and not insanely crazy when Oktoberfest isn't on, you could take the train to Aying and visit Ayinger and then hop back on the train and continue on out to Neuschwanstein to visit the castle. (You have to take a bus from the train stop part way up the mountain, then walk the rest of the way up.)
There are also some GREAT beer tours that leave from the Glockenspiel in Munich that will take you to the first "Biergarten", Schneiderweisse, Paulaner Brewery, and then you end at Hofbrau. -You get one beer at each stop and at one of the breweries you get multiple little taster glasses (at least that's how it worked when I did it 2 years ago).
-I always try to enjoy Dunkel while there as it's harder to find outside of Germany. The Schneiderweiss "Weizen Eis Bock" version of Aventinis is available at the Schneiderweiss pub and exceptionally difficult to get anywhere else. If I remember right its around 14% ABV and is served in a tiny version of a weiss glass. The stained glass windows in the pub all depict the brewing ingredients, process, and Schneider's various beers; beautiful downtown Munich pub; halfway in between the main train station and the Hofbrau haus.
[i:25n8fac3][Edit] -I realize there's an ambiguous reference here; when I say "Dunkel" I mean the style often referred to as "Munich Dunkel", dark lager with no wheat; I also mentioned Schneiderweiss Aventinus which is a "Dunkel Weiss" (Dark Wheat) style. I do NOT wish to further muddy the water as it relates to "Dunkel" and "Dunkelweiss" which are two very different styles that are commonly confused. [/edit][/i:25n8fac3]
Adam
