Alright, so, I finished the anime "Welcome to the NHK" about four years behind everyone else. For the most part, it held up to the manga. I was a bit disappointed that it sort of beats you over the head with "The Message", even if less than the manga, and even more disappointed that Hitomi wasn't as deep in the anime (she's still my favorite character, though). The scene on the cliff, with the Off Meeting, was just plain ricockulous, too.
For the most part, I did enjoy the anime, but felt sometimes that they ran out of ideas at times and so hit on the same themes over and over.