In the early 2000's a friend offered to take me on a ride-a-long at a track-day event he was going to. Man, was I hooked! Talk about some serious adrenaline, and G-forces, and speed! It's certainly not the worlds most cost-effective hobby, but nothing is quite like rocketing down the front straight of a track like Thunderhill at over 120MPH. I've also enjoyed track days at Sears Point, Buttonwillow, and the Lone Pine air strip (high-speed autocross.)
Over the years I've owned a number of of track cars. My first foray was with a C4 Corvette (1995) - Largely stock, except for safety equipment.
My other track car is frankenstein Z, although it's currently non-op. Once my kids get closer to driving age we're planning to rebuild it (likely as an electric car) at which point it'll be ready to head back to the track.