I'm a big fan of the SS100 in terms of pre-war because Jaguar from the start made something as quick as anything but at a more competitive cost. Set the tone for everything since and IMO the new XK is quite possibly the best value sports car on sale. (Not that I have £75k kicking about but hey - just look at it next to a Vantage.)
In terms of other stuff I really like Voisins, Alfa 8Cs (Tazio Nuvolari being a hero of mine), Talbot Lagos and Bugattis (well, who doesn't?). Can't forget the Bentley Speed Six either...
