Wow! I'm blown away by two votes for Sabino Canyon! It is really nice.
It's funny, I looked for a picture online, and the pictures are really underwhelming--nothing like the ones posted here. But you absolutely have to be there to experience it.
I think part of it is the hike in -- you have to work for it. Part of it is the contrast to the surrounding arid desert. But mostly, I think it's a very accessible human scale. Not like the massive mountain vistas here. Something you can see from across the canyon, and then climb a little more and dive right into.