EDIT any of the bigger beemers E34 as I had the 6 pot petrol manual and it was amazing. Once I fixed the over heating, viscous fan failed and new water pump and thrermostat it was great. Had different suspension rubbers replaced at every MOT. Absolutely great at oversteer fun.
Having only had experience with Honda's B18 engine, I'm keen to try something K20 powered. It seems to be the engine to slot into pretty much anything at the minute. Add a Turbo or supercharger and it opens it up further.
Beemer E30...if you can afford one.
EDIT any of the bigger beemers E34 as I had the 6 pot petrol manual and it was amazing. Once I fixed the over heating, viscous fan failed and new water pump and thrermostat it was great. Had different suspension rubbers replaced at every MOT. Absolutely great at oversteer fun.