Extreme Metal

[Maddolis]

Whoaaa that's a real nice post!
Respect for taking DF off your list- if you still like them you shouldn't be afraid to listen to them- then again if you are just now getting into power metal, I completely support your decision because you will find stuff you enjoy and eventually dislike DF for sure.

Those 5 albums you mentioned are all really important in the creation of various genres- Cowboys from Hell is just a sweet thrash album (and was one albums really leading into Pantera pioneering groove metal).
Megadeth's Rust in Peace would be one of the greatest thrash albums, JP's Sad Wings just massive in heavy metal, Black Sabbath's Paranoid same thing, and In Flames' Jester Race (as I said earlier) is one of the 3 pioneering albums in Gothenburg Melodic Death Metal.

If you really enjoy The Jester Race, I'd suggest you listen to 'Whoracle' (the next In Flames album) and/or Dark Tranquility's 'The Gallery' (another of the 3 albums pioneering Gothenburg melodic death). It wouldn't expand your listening terribly far but if you really love The Jester Race, you should give them a listen.