Well Franco seems we have similar tastes in cars but I would struggle to pick just one.
FG F6
E39 M5 (probably my favorite sedan of all time)
Alfa 156 GTA ($15k gets a good one...yeah yeah FWD but that engine and style is ace)
VT2-VE HSV Clubsport (yeap one day I actually want one in the garage)
Toyota Chaser V (but the F6 would be better)
I could go on forever, but if it was for a daily and maintenance wasnt an issue the M5 wins. Fast, practical, timeless design.
If I could get away with a coupe then the E46 M3 (manual) is next.
https://www.carsales.com.au/cars/det...-6535763/?Cr=0
That one has come down $5k in the last 2 weeks.