For me, it'd have to be somewhere that's about 2-3 hours away... and with someone who is fun to be around. If you're gonna be trapped in a car with someone, ideally they are a fun person! Or they share your taste in music haha!
I'm not a fan of huge road trips. I used to drive to college sometimes, and that could be a 10 hour plus drive! Boo... after a while, I wised up and started taking the train.
What is your ideal road trip? Both length of drive, and where you'd want to go... and who you'd want to go with too!