I just finished reading a book I'd meant to get to for awhile, but had never gotten around to. That's A Confederacy of Dunces, by John Kennedy Toole. Wow. It's a shame that Toole killed himself when he had only written two novels, and before either had been published. He truly had a gift, and it would be hard for me to point to a better example of a satirical novel.
Two things about Ignatius J. Reilly. One, I know people like that. Maybe not down to the last detail, but some of the major characteristics. The old-time religiosity, the submerged sexual perversion, the codependent relationship with a doting/abusive mother. As absurd and exaggerated as he may be, Reilly seems real to me.
In addition, a kind of transformation happened in regards to my view of the character. He's overly proud of his (not really exceptional) scholarship, and he's generally unpleasant to everyone, sometimes destructive. At first he's a supreme irritant. But gradually I found him earning my respect. Part of it has to do with comparison between him and some of the other characters, by which he actually does come off a lot smarter. And it could also be the author's affection for his own creation rubbing off on the reader.