I donate blood every 8 weeks and I wouldn't go anywhere else but here (I drive from Tempe... it's that good).
Bonnie, at the front desk, might be the nicest person that I've ever met. She's never not smiling. In the 1.5+ years that I've been coming, I haven't had one bad phlebotomist experience or even a bruise on my arm - that's pretty amazing in my book. The entire staff makes the experience enjoyable which is a tough thing to do when you're getting stuck with a needle.
On top of that, they have a popcorn machine. Not into popcorn? Don't worry, they offer some other great snacks and drinks.
Pro Tip: Fill out the questionnaire online before to expedite the process.