Tough call, probably a tie between most recent and a couple of years ago:

2009 - BA with MFU to PEK (op-up to F at gate on return too), then on to North Korea with Air Koryo. Met the definition of getting away from it all, a fascinating country and unique experience. Most people quite friendly, but at same time you could see the way they were brainwashed and some extreme examples of poverty. Not much individual customisation possible, but Koryo Tours are great at organising trips and the Yanggakdo Hotel is passable (bowling alley and casino in-house). Seeing the Aritamg show is a must.

2011 - NZ and South Pacific, AY to BKK and BA to SYD with LAN to AKL (bit of a marathon, kept me Gold too, thanks to FT! Did use the "other side" with SQ reward flight from CHC to SIN on return). Highlights in NZ were seeing Ireland beat the Aussies in the rugby world cup, and enjoying the many activities around Queenstown - Browns Boutique Hotel had a great atmosphere and views. In Tonga swimming with humpback whales is phenomenal, Serenity Beaches on Ha'apai is basic (generator on sometimes, no hot water) but very welcoming and let's you get away from distractions.

In case anyone is as deranged as me when it comes to holidays and wants further colour just PM me