Yeah, I was gonna say.... Mitch Hedberg is at the top of my list, along with the like of Carlin. =)
I love Louis C.K. too, and Ricky Gervais, and Stephen Merchant, and Gabriel Iglesias, but of all the comics I find myself quoting when I'm all by myself and I can only keep myself company with my own thoughts and memories, Mitch Hedberg's and George Carlin's skits are what come to mind, the most. I prefer Carlin's works up to the last 2 years of his life, as I feel that he really let himself sink into conspiracy theories and big-brother paranoia (not that he was completely off base, just that he was eventually quoted agreeing with all those "The Government was behind 9/11" nut jobs) and it detracted somewhat from his comedy near the end of his life. But the sheer volume of amazing content that he provided in the decades prior to that makes it forgivable, to me, and he remains as my all-time favorite comedian. I just wish Mitch Hedberg lived a little longer so he had a chance to provide us with more of his brilliance, too... =(
"Bears can be mean! But a frog is always cool! ... If a frog comes around, I don't have to hang my sandwiches from a branch! You'll never hear somebody say, 'Aww shit, here comes that frog; I better play dead!'"
"I went to the store to buy a candle holder, but they were all out, so I bought a cake!"
"I love escalators, man, because an escalator can never break; it can only become stairs! You will never see a sign saying 'Escalator temporarily broken' no, you'll only see 'Escalator temporarily stairs; sorry for the convenience!'"