River rafting - My dream (one of many) is to raft the Zambezi River on my raft Zantara Azul.
I don't just face challenges - I raft them
http://uk.youtube.com/watch?v=di1SenT1bRY&feature=related
Dancing - Ballet, modern, swing, tango, ballroom and recently line salsa and line dancing
Reading - I can't resist a good book. And I love the smell of an old volume.
History - World history because the applications are endless and the characters, places, events, and ideas are incredibly intriguing. Discovering the reality behind the often dull facts included in history text books is a hobby of mine. Nobody is perfect and we have a tendency to idolize humans we would be better served by learning from. Their mistakes are often as important as their victories.
Museums - A wealth of knowledge awaits.
One of my favorites: http://www.getty.edu/
Travel - Anywhere and everywhere. So much to learn and discover!