One of the perks of our community is having bars specifically made for us.
Some are great opportunites to meet like-minded people, and others.. don't have such a great atmosphere.

La Citadelle in Geneva, Switzerland was where I had my first drink, so it still has a special place in my heart even though its users are usually fairly young. 
The Rock n' Eat in Lyon, France I visited regularly during my studies. Not all that impressive, but nice enough for a night out.
Visited some more metal bars here and there but none really worth mentioning.

The best metal bar I've ever been to was a small one, in Rovaniemi, Finland: the Paha Kurki Rockhouse.
Rather small, but such a great atmosphere and super friendly regulars and staff! Although finnish people are known to be rather shy to new people, they were easily corrupted once everyone started drinking and the metal yelled loud enough. I'd visit it again if only Rovaniemi was easier to get to. If you're ever in the area, it's definitely one of my top recommendations.

How about you all? I travel a lot, so any recommendations from anywhere is valuable to me.