Hmm, I really really really don't like Japanese boybands, so it's kind of depressing to know that they seem to get some of the best concerts... XD
As others have said, Nana Mizuki's concerts are badass ^^ Especially LIVE DIAMOND, as noidea recommended. Definitely one of the best concerts of 2009. Her performances do seem very Ayu-inspired, imo, and she has like... a million "epic" songs, so you can expect a lot of epic performances
