I always think of using Marriott points for hotel stays as the best value. I think of expensive places like Europe or Japan for my best redemption value. But coolest trip I did that was mostly Marriott properties was Brazil, Argentina, and Chile.

Started out in Rio (JW Marriott Copacabana) for New Year's. Spent six days there. Then flew to Igauzu Falls (Sheraton only option there). Next stop was the Marriott Plaza Hotel Buenos Aires. Spent five days there with a side trip to Uruguay. From BA, flew to Bariloche and did a crossing of the Andes (Best Western/local place in Barilcohe + one night at a lodge in the middle of a national park + local place in Puerto Montt). Final flight/stop was up to Santiago and the Santiago Marriott (with side trips to wine country and Valparaiso/Vina del Mar) - 4 days total there.

The options above sound great too - just adding another option. The Marriott Cairo in Zamalek may have been my favorite exerience in Cairo if you go that route (though rates were cheap - not sure I would waste points).