Personally, I would say get more points to get the season pass since you are purchasing the Season Pass as if it was buy 3 DLC and get 1 Free. (They will take the season pass off soon before they plan on releasing DLC #4)
If not, I would say Torgue for the comedic dialogue, Hammerlock's Big Game Hunt, for the Combat, and Pirates Booty for the story. Whichever you would think you like. --- XBL GT/PSN: Tsuruke.
I'd say probably Pirates Booty then, from what I'm hearing. I'm not really into farming much (I do a little here and there) but I hear about some good stuff coming out of that DLC. --- Joy puking my face off
Torgue is by far the best one (not saying much), but comcast gave away TONS of free DLC codes for Torgue and many greedy gamers grabbed them in bulk. A code for the DLC now goes for 2 - 5 dollars, so you're best off buying one of those codes and spending the full amount on one you can't get for less.