The Drunk Tank. Or as it's now known, The Rooster Teeth Podcast
. I started out on Smith's SModcast as well, and while SMod sort of turned into "Smith gets stoned and laughs at his own jokes" all the time, The RT Podcast has always been hilarious.
I guess it helps if your a fan of Red Vs Blue/Achievement Hunter as well, but really the humor ranges from Game/TV/Movie releases to....Gavin's genitalia. But still, its a hilarious listen (or watch, as its now a live video podcast, although you need to subscribe to Roosterteeth as a sponsor to see it "live", otherwise it's released a week later on youtube).