Either of the Slings is worth trying, especially if you haven't tried before.

As for cocktails, SQ has one of the most extensive lists amongst the airlines. My go-to drinks would be Choya Umeshu mixed with soda served on the rocks, and their more recently-introduced super delicious Peach Bellini. However, some flights may not be stocked with Cointreau (unsure if the supply chain issue still persists till today) so you may be told that any orange liquor-based cocktails may not be available.