The best WoW clone I’ve played was RIFT, hands down. That game was surprisingly well-polished. But unfortunately the last time I had returned to play it, they followed suit with other popular MMOs and nerfed the overworld content into oblivion, effectively ruining the experience.
I did appreciate their angle on the class system, though. By combining Pyromancer and Elementalist, I was able effectively mimic a Fire Wizard from DAoC, but with a bad-ass greater earth elemental as a tank pet. One of the most satisfying characters I’ve ever played in an MMO.
Still, Classic/Vanilla WoW was a better experience overall.