I was thinking either I'd purchase them a DLC or give them XBL Points, or in-game gear (that I farmed myself). I can also make posters of characters in the game and customize them with whatever text in whatever font.
What do you guys think would be a good giveaway to a random sub?
XBL GT: Ki11er Six (ones instead of L's and a space between the two words) Various Borderlands 2 glitches: http://www.youtube.com/watch?v=ZgdactVBsYk
Honestly, in game gear. Why? You're actually getting people who are interested in the game and could be a long term subscriber. Why not points? Because you'll just get a whole bunch of subscribers who NEED points and not interested in what you actually have.