I've talked to a couple people who have at least heard of Disgaea but are afraid to get into it, because they're afraid of how deep and complicated the battle system might be. Haven't converted anyone yet, though I had a friend who had just begun to play D1, when his game got stolen.
When I picked up Disgaea 4, I took it to a fast food joint to read the book and peruse the art book during lunch. A waitress saw it and thought it was from an anime that her nephew or somebody was into.
The only anime I have ever watched was the Disgaea one (does two episodes of One Piece I watched with a friend over the internet count?).