I've actually been to 3 Hofbrauhauses - Munich, Las Vegas and Pittsburgh. They're all a little different, though I've had very different experiences at each. Munich is my favorite.
How can you not love the Hofbrauhaus in Munich? The place has real live German's in it, what's not to like? But I also like that the place is hundreds of years old and although it attracts lots of tourists, it's still a place that locals go to. I'm sure the Hofbrauhaus people hate this, but I also like the painted ceilings. In the 1930's when the Nazi's were coming and in power they often used the Hofbrauhaus and they painted the ceilings with swastikas. After the war they tried to paint over them, but the red kept bleeding through. They ended up painting designs around them. What I like about this is that it's there if you look, but it's not so apparent that you feel its presence when you're there. The ceiling was recreated at the Las Vegas restaurant, but not at the one in Pittsburgh, which was a disappointment to me. But in Munich, the food was good, the beer was good and the atmosphere fun and energetic.
I've been to the Las Vegas restaurant twice, but I've always gone for lunch with my family. It's not terribly lively there at lunch time, but it's a good place for a big group. The food is good, but I LOVE the pretzels there. I guess I should get my butt there one day for dinner. My brother-in-law who is more of a foody then I am and has been there more recently didn't seem terribly impressed with the food the last time he was there.
Pittsburgh, I've only been there once but enjoyed it. It's a large restaurant and it has a quiet room incase you want the food and not the band. It also has a patio/beirgarten, there was a gravely flooring here so leave the cute heels at home. I thougth the food was good not great, but the band was good. The pretzels were not the same as the ones in Las Vegas or Munich and weren't as good. My biggest disappointment was in the design. From the outside it has the HB look, but inside it doesn't have the contoured ceilings or the designs on them. It felt like they cut a lot of corner and made it more like a "Western" beer hall instead of it's older German sister.