Worst 1973 Opel Manta, brown. Just. Plain. Bad. However, many girls from my town do recall the interior...
Best 1995 Infinity J30, blueish (no, not purple, it just looks that way in the sun). First real luxury car, drove like nothing at the time. Of course, now my gargantuan (not purple, either) SUV would beat in in any race, but at the time, it was the best.
My worst...had to be my 1965 Mustang that was rear ended so I found a 1966 Mustang that had a front end wrecked and had the rear of the 66' welded to the front of the 65'. The drive train had been damaged so the transmission had to be repaired every three months or so. I had the heads shaved and it would run a good quartermile. I traded it in for the Opel....