For this first post I only mention some of my favorites, in no particular order (although the first mentioned might very well be my #1...). Also. Didn't take long with taking pics online, so can't promise the best possible quality available.
Stratovarius - Visions by Andreas Marschall, who did lots of artworks especially in 90's for metal bands such as Blind Guardian, Running Wild, Sodom, Kreator, Grave Digger, HammerFall... Blind Guardian not only having one of the strongest line of power metal albums in 90´s, but also they are all with Marchhall's great art.
Heavenly - Dust to Dust by Jan Meininghaus, who has worked on many artworks and designs. Did a lot of cover arts for the band Falconer. Dust to Dust artwork is perfect fit for the story of this concept album.
Sonata Arctica - Silence by Eric Philippe, who is also known for early Rhapsody cover arts. Also made Twilight Time for Strato. I've seen Silence cover getting very mixed opinions, maybe because people don't quite get it. For me it's by far the best there is for SA. I remember there being a poll on long gone Sonata forums where it took the win for the best album cover the band had (Unia being the most recent album/option on the poll at the time)
Stratovarius - Survive by Gyula Havancsak, who also made everything for Stratovarius ever since Polaris. I've liked each and every one of them but still something in Survive managed to surprise me.
Helloween – Keeper Of The Seven Keys - Part II by Uwe Karczewski. Known for first three Helloween albums and two first EPs, all excellent inside out. He passed away in 2021.
Helloween - Helloween by Eliran Kantor, very active artist in recent years. My expections were high for the songs of this album at the time, but one of the biggest positive surprises came in this artwork. Glad he was chosen for "Giants & Monsters" as well.
