This is a tough one, genuinely - do you go for the Williams which was a magic car, in the same way the Trophy is, in fact it would be fair to say that the Trophy is "only" a modern Williams. Or do you go for what started the breed ie Peugeot/VW/Alfa (my choice being the Alfa as I had one) and of course the Mini or the Integrale (although to say that is a hot hatch is pushing it a bit)...
In fact this is quite hard, as I've had the 5! (Mini, AlfaSud 1.5Ti Green Cloverleaf, Integrale, Williams, Trophy), the Trophy is the best, but that is only because it is the most modern ... I'll sleep on it.
As much as the term hot hatch to me seems to be applied to anything that has a hatchback body which OK is where the term came from, I consider the integrale, Escort Cosworth & Nissan Pulsar GTiR to be in a completly different league to what I consider hot hatches, affordable quick versions of the smaller cars of manufacturers ranges which can be found with low power engines.
i.e. 106 Rallye, Trophy, 205GTi etc and I would discount things like Golf R32 as more of a luxurious grand tourer than a hit hatch.
A real hot hatch is something available to the masses at affordable prices.
BUT and it is a BIG BUT if someone insists in classing all these cars together the integrale is peerless due to it's uncompromised development to be the most successful rally car of all time. 6 manufacturer WRC titles in a row, 4 drivers titles, 44 WRC victories and that's before you even get to the european & worldwide domestic championships.
So I had to vote for it as much as I love my Trophy & in my mind is a hot hatch not a magnificent rally refugee that happens to be in a hatch back body.