Ok, time to throw some numbers into the fray..... They might dispel some of the "F-4 invincibility Myth".
Admittedly, I don't know as much as I would like about aircraft like the Lightning or the Mirage, so someone feel free to add the numbers from those aircraft.
This data comes from "Clashes, Air Combat over North Vietnam 1965-1972". Its only accurate for a general comparison, but should be helpful
Gross Weight(lbs) Max Vs (SL, knots) Thrust/Weight Wing Loading (lbs/sq ft)
F-105D 52,000 730 0.745 92
F-4 53,000 710 0.79 81
F-8 30,000 650 0.69 69
MiG-21 16,300 595 0.88 58
MiG-19 16,500 620 0.84 51
MiG-17 12,000 575 0.64 44
Now, don't get me wrong. The F-4 was an incredible aircraft, and extremely versatile, especially as a fighter-bomber. But as a pure fighter it has problems. Its two man crew, radar and BVR capability, and high speed/power makes it an incredible interceptor. These systems would mature as the 70's went on to make it the best fighter in the world at the time. But without pulse doppler look down radar, systems failures (common to this period), or ROE that precludes BVR shots, it would have a very difficult time with some of the other pure fighters listed here. And lets not forget that other planes here also have a limited BVR radar guided capability.
Also lets consider size of the aircraft (ability to spot it), view out of the cockpit (see the enemy), and such things as smoking engines. So do you still think the F-4 is the best in terms of fighter capability only?
*stokes the fires of discussion*