Mixed feelings for me. On one hand, represents the peak of WoW's popularity, a significant step up in visuals, a story and setting surrounding Warcraft's most popular antagonist(s).

But on the other, i can't help but feel this is where the rot set in. Here the game got noticeably more linear, and the introduction of the dungeon finder basically removed the main incentive to join guilds and form communities, and also took away the need to travel physically around the world to visit dungeons, making the world feel much more empty. There's a reason they didn't bring it back for WotlK classic.