I just listened to Circus Maximus for first time yesterday and was really impressed with what I heard.
I post over at the John Petrucci board & there is a ton of talk about them over there. I really need to check them out, I just think the name is ridiculos, but if they make good music I will get over it soon. They're the next Power/Prog band on my list to check out.
I
love Symphony X & Yngwie. I've always looked at Yngwie sort of as one of the father's of Power Metal, along with Iron Maiden.
Firewind's first album was very very good, after that they got relentless, but had some good tracks.
Evergrey is basically 1/2 Power & "In the Search of Truth" is a decent album to at least check out to see if you like it. I think it's a good album, but not great. A ton of people love it.
Another PM band I had a brief phase with was Kamelot, but now I can't really listen to them & I wouldn't recommend anything by them personally.
I have "Nightfall in Middle-Earth" & the new one by Blind Guardian... Meh... I just can't get into them. They're a little too jolly for my tastes. "Nightfall" is a great album for what it is though.
Nightwish could be perhaps classified as Power Metal, although I personally have a tough time calling them that. "Oceanborn" is an amazing album that I think everyone should offer a chance to.