I happen to like Nightwish. Not their first two albums, but everything after that.
And I generally don't listen to bands that use the same old Dungeons and Dragons lyrics. Don't get me wrong, some of them have amazing musical talent (Rhapsody, for example) but just don't offer anything new or meaningful.
Mahavatar, just want to say Mahavatar. if this is not progressive then what is? Go for the no! was an album that showed the ape men how women rock the world, this is our music, there will be a new album soon
Blind Guardian is a power metal band akin to DragonForce, not as many speed/thrash metal elements to them. And Nightwish are symphonic metal, it's a strech to categorize them as power or progressive, methinks.