Just got back from their concert. A-mazing. If they're coming anywhere near you, don't miss it. Worth every penny. I'm a big concert buff, too... I've seen all different types of concerts ranging from typical modern rock to classical symphonys to celtic music. So if I recommend something, it's for real. I'm sure you've heard their songs before (a lot of people have been posting that house with flashing lights, that's one of their songs) but it's nothing like seeing them live.
Christmas music + 2 electric guitars + 1 electric violin + drums + lasers + pyrotechnics = win.
They basically take popular Christmas songs and turn them into stunning guitar solos. They do actually have an orchestra of about 20 violins, cellos and such to go along with drums, 2 electro pianos, 1 electic violin, etc. Not to mention, this isn't all about the instruments. The singers are just as equally stunning, these aren't your typical 70s metal voices. The best name I could give it would be Rock Opera. It's just incredible. See them
http://www.trans-siberian.com/intro.html