Anthony Davis should absolutely be in the discussion. I understand he still has a couple of seasons to go before he is leading his teams deep into the playoffs, but he is probably the most valuable chip in the NBA today. Paul George should probably also get a mention.
Anthony Davis would already be on my list. He's been that good this season. Paul George is borderline.
Here's my take (numbers are for groupings, not ranks)
1. LeBron, Durant
2. Paul
3. Griffin, Curry, Harden, Davis
4. Duncan
5. Love, Carmelo
6. Noah, M. Gasol, George, Parker, Westbrook
7. Dirk, Dwight, Aldridge, Dragic, Cousins, Wall
I'm not sure where the list really stops -- after level 4, 5, 6, or 7.