Neither.
The deadliest aviators in the skies wear the eagle, globe, and anchor!
<insert Marine Hymn here>
Actually, if you plot the bell curve of pilot skills, tactical expertise, and training...all 3 branches with TacAir probably overlay each other with little overlap.
Back in the day, it was obvious that the USAF abandoned the "work on what ya need to work on" way of life, and adopted a doctrine of deconstructing each aspect of mission employment, and working on it until you have it wired. When the 4th generation fighters arrived (F-15, F-16, etc) the new doctrine worked, due to the change in emphasis from instinct, to weapon system employment.
Developing the correct "contract" within your flight of fighters, and then sticking with the plan has made them very successful. All-aspect missiles can make any dweeb the Red Baron if he drives a point-and-shoot jet! The new gouge is getting to the merge with all the bad guys in the 'chutes already.
The Navy has always put emphasis on how you look around the boat, and being able to improvise tactically. The F-14 caused some problems initially in the fleet because most of the squadrons flew it like a Super Phantom, and didn't develop tactics as quickly as the USAF.
The Marines were still fly their Dad's jet (I did!), put an emphasis on putting the bombs on bad guys close to the good guys, knife fighting air-to-air, and trying to avoid a PCS FAC tour!
For a while, the 4th generation fighters were better than the pilots who flew them. The gizmos could do more than the gizmo operator could optimize.
Top Gun, FWS (USAF Fighter Weapons School), and WTI (Marine Weapons & Tactics Instructor school) eventually adopted the USAF method of super-jet training, and all 3 services seem to be wringing all of the capability out of their aircraft.
The "best" are those that are getting the most flight time that month, either in real-world ops, or in training that is as real-world as the budget allows.
In conclusion, the best are the Marines, because the rest are pansies.
<Marine Hymn fadeout>
P.S. As far as who the best trash-hauler, tanker, helo, and patrol pilots are...who cares?
