I got to sit in a Funny car with Kenny Bernstein standing by me with the motor on (but throttle/controls disengaged) as a kid in the 80s at Ennis. It was some photo op thing, I bet that never happens anymore. That thing was LOUD, and I remember some posters saying '300mph'. I actually went zero mph, but it was a ton of fun anyway. I think those cars are in the multi-thousand hp range.
Fastest car I've driven is a CTR3, but I was not able to give it any throttle at all. It was on the side streets of RUF/RAC, and I drove it for about 1/10th mile and a single turn before pulling over and swapping back. Riding was hellishly fun though.
Fastest car I've legitimately driven is now a C5-R that one of my clients has substantially upgraded motor wise. The last dynos were only about 700whp, but that was over a year ago, and since then he's built up a new Katech + Eaton setup that he says should be good for closer to 900. I believe him. I did not come even close to pushing the car to its limits, but was able to feel a 30-80 push like I've never seen before. It made the fastest car I've ever owned, an E39 M5 6MT, feel downright anemic in comparison.