I have to admit, ive been having a ton of fun in this expansion, and the only other expansion in WoW's history that has come close to keeping my attention on the game as well as Legion has is TBC. That being said, I think there can be made a good argument for Legion being one of the best expansions of ANY mmo out there on the market.
Things that keep me playing:
- Replayability - Tons of stuff to do, and even more if you have alts
- Gameplay - Blizzard was spot on with the gameplay of the expansion from a mechanics perspective
- Fun, yet challenging - The game strikes a perfect balance between being too easy, and challenging. Several of the outdoor areas can be challenging without decent gear
- Outdoor PvP - Love the world quest outdoor PvP areas. Especially the Blackrook arena and bearback brawl in Stormheim
- Raids - Some of the best the game has ever seen
- Lore - Story has been superb and its tied very well this expansion
- Dungeons - Mythic+, what more needs to be said?
Overall I rate Legion 9.9/10 and A++. I'm excited for what Blizzard has in store after Legion as well.