In the past Sonata Arctica wouldn't have really been qualified here as a progressive metal band, but I challenge anyone to debate if their newest album,
Unia, is progressive metal or not.
I just got the album a while back and I must say I love it! I'm been a semi-fan of the band earlier with a few good songs here and there on their albums but this album just beats them all - and a lot of the other albums released in 2007.
Sonata Arctica has taken a lot of Queen-style solutions to their music, and they got out of the traditional genre of power metal. Their songs are more complex, more fun to listen and while the lyrics still tend to be rather naive, the vocal melodies are really awesome!
Anyhow, below some links to youtube for songs. Just to give you an idea what they're about these days.
Sonata Arctica - It Won't Fade (youtube)Sonata Arctica - The Harvest (youtube)