Depends on your criteria - I think Hall is a fantastic player but it's his intangibles that set him apart from the others.
RNH
Hall
Schultz
Yakupov
Eberle
Now, Eberle is my favorite player (in the league). I'd hate to see him go. But Hall brings more to the table (aside from scoring) to the table. RNH's upside is immense, he plays a solid two-way game, and plays at C which makes him the most valuable of the bunch by default almost. Hall and RNH are definitely my top 2 - the bottom 3 you could rotate but Schultz is proving to be a dynamic player and again, in a position the Oil sorely need, so he gets the bump above the other two. Eberle vs. Yakupov comes down to one thing... and that's the fact that Yakupov will likely turn out to be the more dynamic scorer of the two.
Skill-wise, Hall is probably down the list a bit but the intangibles he has puts him at or near the top. Plus, if you buy into Corsi and all that, he's been one of the best wingers in the league over the past while. He simply brings to the table things no one else on the team can and is really the catalyst on whatever line he plays for.