Right now there are couple of collected works in the Thor library called the Eternals Saga. The original issues comprising this story arc numbered around 20, including an annual. The saga culminated in the double-sized Thor 300 with Thor 301 being an epilogue issue.
The Saga is memorable to me because it was one of those moments when a good comicbook, Thor, became a great comicbook.
The Eternals Saga had the Celestials, the Destroyer, and Jack Kirby’s Eternals. It not only had the Norse gods but the Olympian gods as well, with Zeus and company being hoodwinked by Odin to attack the Eternals. The arc featured the enigmatic Forgotten One, a superstrong Eternal that could go one-on-one with Thor, and did, to the amusement of the celestial known as the One Above All – a celestial that outranked even the might Arishem.
The Saga featured many wonderful battles, and just like a boxing match, we can rank them up, with the main battle being between the Third Celestial Host and a gigantic Destroyer powered by all the collected lifeforce of the Asgardians. The Eternals Saga is a Marvel epic with a capital E.