The only power metal bands I really like are Iced Earth and Sonata Arctica (good taste, GuitarPsy ;)). Iced Earth were one of the bands who really kick-started the power metal trend, and while I'm not usually a supporter of the "they-did-it-first-therefore-they-do-it-best" theory, I think they have a great feel for the spirit of the genre which many of the younger, more over-the-top acts like Dragonforce and Helloween just don't have. Sonata Arctica are also great - their lyrical style really stands out from other bands in that scene, and their guitarist Jani has more talent in his little finger than Herman and Sam from Dragonforce have put together, IMO.