It's hard to pick just one. South Africa was always a dream for me so just being there on a private game reserve with all the wildlife in natural habitat was awesome. Being within 20-30ft of a male lion as it roared. Watching him summon the roar from deepin the pit of his stomach. The hair still stands up on my neck when I think about it.
The contrast in the country, from pine forests and lushness in the Highveld to the barren sparseness of the Lowveld was something I wasn't expecting. Also on our trip we had a change in the itinery and ended up in St Lucia and I wasn't disappointed. All those crocs and Hippos and the Indian ocean breaking in the background as you tried to sleep.
The spectacular Drakensberg, and the glamping. The scenery here is breathtaking. The hike up "the ladders" was amazing. Seeing people conquer their fear by going up and the whole group, who were complete strangers a couple of weeks before, totally encouraging each other as if they were friends for years. Also on our hike in the Drakensberg we had snow. I didn't expect to see snow in South Africa.