We were discussing this on another thread. Here are my every day hooches (hint: buy 1.75L bottles for MUCH better economics) for making an after work cocktail, or bunch of cocktails for a party:
Sauza Hornitos, El Jimador, or Camerena, either silver or reposado for Margaritia.
For Manhattan's I am all over the map, and typically use bourbon instead of rye:
Evan Williams, Jim Beam, Old Overholt
Rums, really depends on the drink.
Coruba, Cruzan, Goslings, Mount Gay, El Dorado, Don Q (which I haven't seen lately). I love Brugal Anejo for a delicate sipper, but is has gotten a tad pricey lately until I caught it in a 1.75L bottle at a great price: $23 or so.
Gin: Tanqueray, Seagram's is surprisingly good, as is Gordon's.
Vodka (I don't drink much vodka, but Sobieski is great vodka at a silly cheap price.
Sazerac is tricky: lately I've been using 50% Rittenhouse and 50% either Old Overholt or Wild Turkey Rye. Not particularly happy with this though. Gotta find some of the higher proof Wild Turkey.
I am sure I will think of more...