Google for "farmgirl fare toffee chip shortbread" and you will NOT be sorry.

These are great b/c they don't spread much, so although you can scoop them as little drop cookies, you can also roll the dough easily and slice into squares or diamonds with a pizza wheel. Then put them on a parchment lined baking sheet and you don't have to leave much space between them at all (1/2" is plenty). That gets all the cookies baked in 2 cycles of the oven. I put the dough on parchment paper, cover with plastic wrap, and roll it to be about 1/8 - 1/4" thick, then freeze for 5-15 min so they pop off the parchment easily.

To me, the lengthiest part of making cookies isn't mixing the dough, but baking tray after tray of cookies. That's one reason I like shortbread-like cookies, they don't spread as much so you can fit more on the baking sheet.

If you make the same cookie dough multiple times, you don't have to clean the mixer in between each batch. When I need multiple batches I usually mix up 2 (as opposed to doubling the ingredients in one batch).

Ginger snaps. I can't remember where I got the recipe I used last year but it seems like every time I make them I end up with a ton! And they're perfect for the holidays.

Love these Swiss Cinnamon Crisps:
http://www.seriouseats.com/recipes/2009/12/serious-cookies-swiss-cinnamon-crisps-recipe.html

Biscotti are always good too. Most recipes make quite a few cookies at a time and, as EngineerChic points out above, you can bake them all at one time. Plus they hold well. You can either freeze them if you want to get way ahead, or they'll hold unfrozen for over a week. They pack and ship well too.

I go with the kitchn's sugar cookie recipe listed above. My only deviations are reduction in sweet and sometimes I'll mix in whole wheat flour. It is a kick butt recipe.

This recipe for chewy peanut butter and chocolate chip cookies is a good one
http://cinnamonandsouth.blogspot.com.au/2012/09/chewy-peanut-butter-and-chocolate-chip.html

You can actually freeze the dough for up to two weeks and when you're ready to use it, just deforst it in the fridge overnight. They only take a short time to prepare and bake, so you won't be in the kitchen all day!

I LOVE these dried fruit cookies from Ina Garten. Easy to make ahead and even freeze, then slice and bake as needed. AND you can mix up the dried fruits to be whatever you want.

http://www.foodnetwork.com/recipes/ina-garten/fruitcake-cookies-recipe/index.html

The roll cookie recipe in Joy of Cooking is terrific and possesses many of the qualities Faith cites for the sugar cookie recipe in the link above: It has remarkable handling qualities, can be used to form tart shells, roll in balls for jam or Nutella thumbprints, or cut-out cookies. I find I can use every last scrap as the butter and egg content keep it from getting crumbly and hard when re-rolling.

Bittman's recipe for gingersnaps

http://www.howtocookeverything.com/recipes/aunt-bigs-gingersnaps