Louis C.K. is in the middle of one of those zeitgeist defining runs great stand ups sometimes hit in their comedic primes-think early 70's George Carlin, mid 70's Richard Pryor, mid 90's Chris Rock. His humor is observational & like the other comics mentioned his best bits are fueled by high pressure, precisely channeled rage. He's fearless, ferocious & truthful, all required qualities for great stand up comedians, and his recent routines have a tremendous momentum to them, as if they're spearheads being driven by the weight of his entire career.
Both excellent, but Hilarious gets my nod for having one of the greatest bits on childrearing in the history of comedy, as well as the finest show closer in memory.
His teevee show, which is like a more naturalistic, less slapstick version of Larry David's Curb Your Enthusiasm, is also highly recommended:
For completeness sake, he also shows up in Parks & Recreation season two as Leslie's love interest.
Parks & Rec is tremendously funny & well written, check that one out too if you haven't already.
It's one of those shows I didn't really get into on broadcast teevee that benefits greatly from the commercial-free streaming treatment.