Good ideas @islandinthemist, especially looking at guided trips for itineraries and good routes to link many sites together.  I am a do it yourself type, but it is nice to get tips and routes from professionals.  Lonely Planet has a few useful regional trekking guides I have found helpful (Patagonia, Himalaya, New Zealand, Banff etc.).
I also enjoy history and culture, and have really enjoyed time in the Carpathian mountains, jungles of Laos, Andes/Patagonia, Amdo (Tibet), hiking to temples in China and more.  Understanding the history and culture can go a long way to have a more intense experience.  while you surrender autonomy for guided tours, you often access terrain and people that you can't really do alone.