I'm a big fan of aeroplan. They've got dozens of partners and you can mix and match airlines to suit your itinerary. I am flying on SQ, TG, EY, and AC (all in one PNR), over 30 hours of flying time, with a 3 day stopover in Dubai, all for just 115,000 aeroplan points. It's one of the best FF program out there and I hope they don't change it!