I may be wrong on this one but I'm expecting a clear winner because, much as I tend to favour the Hawker Hunter, I reckon the F-86 shades it, being a pure fighter in the same way that the Spitfire was.

Well if you're counting the Hunter as 1st gen then there can only be one winner for my money.

The English Electric (later BAC) Lightning.

A genuine mach 2 supersonic design started in 1949, first flew 1954. Amazing.

I guess I'd pick the F-86 Sabre.

But that's me.

The lightning, the real one not that silly looking p-38 , really was awesome but as it replaced the Hunter can't really be first gen. But as the Hunter replaced the Metor and Vampire I see where your coming from, but wouldn't that make the F-86 second gen? Ooh I'm all confused now!