As a wedding present for my husband I booked for him to do the Warbirds flying experience - it was a lot of money but it was fantastic...he loved it! Something really memorable and special.
Parasailing over Bay Lake is really good too-we did that in Nov and enjoyed it a lot.
If he is really in to Disney, we can recommend the Keys to the Kingdom tour at MK. This was one of the best things I've ever done in Orlando. I loved every second of it and tell everyone about it.
It's my 30th next year so I'm hoping that I'll get to spend it in Orlando! Hope you both have a great time.