Ah - zombie thread.
For me it was my 1995 Acura Integra GS-R. But even before that I did a few test drives/driving instruction at car dealers. My first was a 1995 Ford Probe GT based on a Mazda platform. I kind of struggled for a bit, but the sales guy was pretty good. Before I bought the Integra, the sales guy took me out in a GS-R tester car. The dealership always had a tester available for this model, and would retire each one at about 5000 miles and sell it before it lost too much value. I probably drove it 15 miles the first time. I also tried out a Saturn SC2 5-speed, but that thing was way too loud with an extremely harsh engine.
When I took delivery of my GS-R the sales guy took me out one more time to practice in a parking lot until I got better at taking off. He had an appointment so it had to be cut short, but I managed to get it home. For the next month I kept on stalling at red lights, but I got the hang of it, especially feathering the clutch on an incline, because a little bit of slip was the only way to start moving without stalling.
All these cars had a light clutch with synchronized gears, so I have no idea how to drive an older stick. One time I needed to borrow my uncle's pickup, and it was a Toyota SR5 without a tach. That was really interesting trying to shift without knowing exactly where the revs were.