It costs me around £300 from London to Japan and back with 2 stopover and London to Rio De Janeiro the same.
On Christmas morning, I booked a round-trip flight from New York City to Abu Dhabi for $178. Not sure that beats Valerie's first class gem, though.
If we're talking miles and points, I booked Los Angeles to Bangkok (stopover for 4 months) to Sydney (destination for 1 month), Return from Sao Paulo to Los Angeles (Open Jaw one month later). This cost me only 70,000 United points, plus $85 in taxes and fees. I took a separate one way business class flight to connect from Melbourne to Sao Paulo!
By far the best flight deal I ever booked was a round trip in 2007 from Rome to Barcelona for $10, all taxes included (it was a random seat sale on EasyJet). An honorable mention also goes to Condor (http://www.condor.com), which has ongoing special offers on their website - in 2006 I flew with them one way from Vancouver to Milan for $99 all in.
Booked San Francisco to Kathmandu, Nepal RT for 575$ in October 14.
booked $178 roundtrip to Abu Dhabi from JFK :)
I flew direct from Calgary to London (UK) for $678 RT which I thought was a steal....