I have always, always wanted to go up in a hot air balloon. We sent my mom and dad up in one on my mom's 50th birthday, and it looked like so much fun. They both loved it! So, it's on my list.
I love spotting them in the sky, and get a kick thinking of the lucky folks in the baskets—wondering if it's their first trip and if it's in celebration of some momentous occasion. (The only time I don't love spotting them is if I happen to be on the back of a horse. Even the most reliable horses in the world tend to be wary and freaked out by hot air balloons...)