Your user name reminded me of one.
Hard alcohol, especially vodka...go cheap!
Especially anything you're going to mix...go cheap.
The people that say you get a worse hangover from cheap liquor, I don't buy that for a second. You're getting a hangover because of the alcohol, not the "additives" or "impurities" that might show up in cheaper booze.
Gray Goose vs Popov...only about 5% of people could identify a difference in a blind taste test if tasting them straight and 0% if mixed with soda or whatever.
Even things like Scotch or Bourbon...I don't want to derail the thread because this is a very sensitive subject with some people, but I've given the blind taste tests to my hardcore Bourbon loving buddies and they are ALL OVER the place...zero correlation between price and taste when they don't know what it is they are tasting. And I'm talking about $1k bottles in the mix here, Papy Van Winkle and shit. I've never seen a guy as pissed as my friend when he chose Woodford over the Papy Van Winkle I think he blew a guy to get.
Freakonomics did a podcast about a high fallutin' wine lover's club that always drank $100+ bottles of wine...they failed miserably at blind taste tests between $15 bottles and $100 bottles....they ended up preferring the cheaper wine.