While I have of course been aware of XKCD for a long time ("No, Mr Bond, I expect you to die"), I'm finally getting around to going through the entirety of the archives. There are many fun bits, but really I'm finding that the really good bits are the ones that people point to--the Say Anything reference, the apartment filled with playpen balls, the elevator button labeled 'zeppelin'...
Still, there's a bunch of stuff that's totally worth reading.