My friend and I recently visited a friend in Scottsdale and we all scored Groupon tix for the DBG for $9 which makes it WELL worth it.
We really had a nice time walking around and chatting and enjoying the scenery. I've got a weakness for flower photos, so I was digging on the Wildflower path the most. There was a butterfly exhibit, but (from previous experience) I feel strongly that they are gigantic insects with pretty wings, so I stayed away. We did see smaller butterflies along the paths, though, as well as hummingbirds.
Bummed that the website lists the Chihuly exhibit on the main page, yet it ended in 2009. Luckily, I saw most of it when it was in Boston last year, but it turns out there are a few pieces near the entrance.
It was a beautiful day in a beautiful place. If you're in the area, I highly recommend it!