Just one? Not possible. Here are some definite residents of my dream garage. One where money is no object, while the other is a bit more realistic.
Money no object:
Weekend Car
Ferrari "The Ferrari"
SUV/Wagon/Truck
This one was tough, hard to decide between this, the Cayenne Turbo S or the Supercharged Range Rover. This truck is insane though.
Hennessy Velociraptor
Daily Driver
A Motherf***in' Helicopter.
Dream garage, grounded in reality:
Weekend Car
Can't decide between these $150K cars:
the GT-R
or the 2017 ZR1 (pic is the Z06):
SUV/Wagon/Truck
Volvo V60 Polestar in the Rebel Blue. I love this car:
Daily Driver
Easy. Give me an M3.
Out of all of those I'd probably realistically be aiming to own the Volvo, however it is sold out.