We had a wonderful stay at Riad Safa this May. The owners and staff are superb - welcoming, but aren't too pushy of services or hospitality, which can sometimes be too much elsewhere in Morocco. The riad is tastefully decorated, and overall vibe is all about comfort and tranquility. We enjoyed a delicious breakfast on the rooftop terrace every morning, and spent a few afternoons relaxing by the dip pool. Our stay at Riad Safa was definitely one of Marrakesh highlights for us, and we would highly recommend. One thing -- there is a minaret next door to the riad, so the call-to-prayer is heard loud and clear. Adds to the ambiance though!
You can see more here: http://www.victorianinbloom.com/2013/morocco-lodging/