I'll be repetitive and again say Zack Lowe. It's worth repeating because he's that much better than anyone else right now.
After that a guy who hasn't been mentioned is Kelly Dwyer at Ball Don't Lie. He's a little more hit and miss than he used to be, but I still think he can hit the ball out of the park when he has to.
Tom Ziller at SBNation is pretty entertaining, and writes really well when he's doing featured articles. Paul Flannery is worth repeating as well.
More humor based but Trey Kerby of the Starters has been great for years. Though the move to NBA.com has clearly gotten him to the point where he probably can't spend as much time on his writing as he'd like.