I think Trout will be more of a consistent top outfielder, but Harper has the potential to hit 600 jacks. Both possess all 5 tools as already mentioned, but I think Harper is more valuable because of the added power. I do think Trout will be a top 5 OF too.
I'd add:
John Wall (who I hate)
Goran Dragic
Jeff Teague
Darren Collison
Jose Calderon
Brandon Jennings (who I hate)
Jrue Holliday
Ricky Rubio
maybe Raymond Felton too
So I'd have Lowry around #22...
He is a bit better than Sessions, but what bosox was saying was that the difference between Lowry and Sessions isn't even close to the difference in Pau and Jordan Hill.