Pinnacle Peak is located just outside of Phoenix and I did it twice in one day. The first time I ran/walked up and then because it was so beautiful, I did it again, but the second time I brought my iPhone so I could take photos on the way.
It's absolutely gorgeous and one of my favorite ones in the area so far. The hike is only 1.75 miles (one way) and you climb approximately 1,300 feet with the highest point of the trail at 2,889 feet. It's not a loop trail so you go down the same way you go up.
One of the pluses of this trail is that it's well-marked so you won't get lost. They also have guides that walk up the path an hour before they close (at sunset) to make sure everyone is off the peak - so no chance of being left behind.
The only downside of Pinnacle Peak is that it can be crowded on the weekend.
I tried it one Sunday morning and even at 6:30 a.m., it was crazy busy. It's less busy during the week.