First of all, you have to realize what the military objective is. Let's take Iraq, for example. The polictical objective is to change the regime. In order to do that you must defeat the Iraqi army's will and/or ability to resist and protect the regime leaders. In order to do that with minimum casualties to our own forces we must first control the airspace above the battlefield . . . called air superiority (ability to control portions/times of airspace) or air supremacy (complete command of airspace). The idea being to be able to weaken or destroy the enemy army by attack from the air. Being an army commander without control of the air above you is fatal, as was proved during Gulf War I.
So, in short, you first conduct a campaign to gain air supremacy with you air-to-air fighters, and SEAD (Suppression of Enemy Air Defenses) assets, in order to be able to operate you bombers without interference. Therefor, the "fighter" assests like air-to-air F-15s become a sort of "support" for the bombers . . . B-52s, B-1s, B-2s, F-15Es, F-16s, FA-18s, etc. The bombers then beat up the enemy ground forces bad enough to make it less risky for the Army's Mech Infantry and Armor to engage what left of the enemy forces.
And THAT, is really the main show . . . the maneuver forces on the ground.
In short, the F-16 is a good dual purpose air-to-air fighter and bomber. The F-15s as a dedicated air superiority fighter, are more heavily armed, have better radar, etc. As a fighter, the F-16 is smaller and harder to see and argueably more maneuverable. Which one is superior? Well, that probably has a lot to do with the training, experience, and skill of the pilot and support (AWACs) etc. From my own perspective as a former heavy bomber pilot, I'd prefer a "wall" of eagles (F-15s) to clear out the airspace and "own" the air, with F-16s and F-15Es configured for ground attack to go after the better defended ground targets, then the heavy bombers to do the heavy lifting of attacking massed troop/armor concentrations, multiple targets, and provide a long loiter times with very large bomb loads (a single B-1 has a bomb load equal to about a squadron of F-16s).
It really is an irrelevant question, however. We're not fighting each other, nor are we adversaries of countries who we've sold F-16s.
