I’ve been to some amazing places (ask Marianne!) but if I had the time and the money I’d go back to Antarctica every year. It is just so gobsmackingly beautiful and so far removed from everyday life.
As tips, I would say the sea kayaking is a must do. It added a whole new dimension to the trip and we saw and did things that the rest of the passengers never came close to. I’d also recommend the night “camping” on the ice. It wasn’t the most comfortable, but was certainly a memorable experience.