I, like many others here, have observed the same thing. Mixers! Mixers, limes, lemons, olives...you get the picture. They are often more costly and run out more quickly.
If you want to gift alcohol to people, I think it's best to go with top shelf (if you can). Being a huge gin drinker a bottle of Plymouth, Bombay Sapphire or Magellan (the gin is naturally blue...so cool AND it tastes fantastic, sort of spicy and it's a strong 88 proof) wont go unnoticed.
Arround camp, it is always nice to have a few beers to offer to people or in your pack. I personally am partial to a hard cider in the afternoon heat.
But remember, not everyone on playa drinks! So be prepared if someone graciously declines your gift.
As far as wine goes...I can't speak for everyone, but at my home base a few rousing rounds of slap the bag usually begin around 4 or 5 and continue on into the evening. Take a bag (the inside of the boxed wine), slap to remove dust, hold over head, consume vast quantities, pass on to the next person. A fantastic way to spend an afternoon, it can get quite roudy. And, in fact, there are SOME decent boxed wines now. This also elminiates the glass bottle which can be a pain to haul home and an even bigger pain if they break and you have to clean the glass shards out of the dust in camp.
Finally moving to SF...can't WAIT!