None are healthy, outside certain arguments about wine, which I'm unqualified to comment on.
As to what's best, I think it depends on your dietary philosophy. With a low carb approach, gin I have found works best for me. Doesn't even take me out of ketosis when in it, and really never threw me off course even when I'm just above ketosis level. Whisky, scotch, gin with sugarless mixers to stay as lean as possible when consuming occasional alcohol. Drink a lot of water with it, and after you're done. I prefer gin and vodka as they seem to give me no issues.
This doesn't speak to liver and other concerns and supplementation, simply speaking about staying lean during summer. If you are not used to drinking gin, vodka, whiskey, etc. be cautious, they all sneak up quick on you.