Opinions? We are an "older" family of 4 with a 26 year old and 19 year old. We don't take a lot of vacations together anymore but like to visit the national parks. We like to hike and be outdoors. What we have liked in the past: Yellowstone--absolutely great! Spent 8 days checking out the many different parts of the park. Grand Tetons: really scenic, but after 3 days, we felt we had done what we could. Grand Canyon: great, but unless we camped at the base, couldn't fill a week. Black Hills, great! So, with that as a bit of what we like, any thoughts as to Banff, Glacier, or Yosemite? We don't want to just have scenery to look at; we want to be able to get into it! Thanks in advance for your experienced thoughts.