Marvel: Moon Knight
I love Ragman. Particularly enjoyed Day of Vengeance and the Shadowpact ongoing that followed.
As for most underrated and unpopular, I pickkk
Matrix(Mae)/Linda Danvers/Earth-born Angel/Supergirl
She was the Supergirl I grew up with, but then Kara came back and everybody forgot she existed.
@JSH92: Day of Vengeance was a mini-series basically dealing with a Spectre gone mad and leads directly up into Infinite Crisis. Shadowpact was an ongoing that followed the magical team formed during Day of Vengeance. It was pretty much Justice League Dark before Justice League Dark.
Didn't know that Ragman got his own mini though. I'll definitely keep an eye out for it now.