>>20495965
Epic is definitely the best, and in many ways the most balanced. It also portrays warfare in 40k the best, and reigns in Space Marines to do what they actually are supposed to do in fluff (surgical-knife strike force).
Gothic is however a very well written ruleset, but has some balance issues. Most notably was in it's initial release. Orks were long considered the 'e-z victory' fleet that nobody really had a problem against. While Eldar started off as the troll-tier fleet. Some erratas, additions to fleets, inclusion of things like Roks and Space Hulks, and the latest PDF rules errata, fixed most of that over time. Necrons also gave Eldar a troll-tier fleet to loathe. But the Orks got a lot in the way of points adjustment, ship and fleet customization, clan representation, and 4 Battleships + a Heavy Cruiser.