I’ve always been partial to Nero Wolfe. He’s a big, fat, beer-swilling recluse who solves mysteries without leaving the comfort of his chair, pouting his lips in and out in a kind of autistic tic while his gargantuan brain connects all the dots. Hercule Poirot is a close second, if only for the novel where he mocks Sherlock Holmes (without mentioning him by name), because Poirot solves mysteries mostly by insightful examination of relationships with human beings rather than, as he puts it, mucking around on the ground with a ridiculous magnifying glass, scrutinizing cigarette butts.
At the entire other end of the spectrum there’s Mike Hammer, the quintessential hard-boiled, two-fisted private eye, solving mysteries with a naked dame in one hand and a thundering .45 in the other. [SPOILER] At the end of one book he’s just gunned down the woman he loves and plans to marry because she turns out to be the one who killed his war buddy. As she’s bleeding out on the carpet she asks, “Mike, how could you?” And he looks her right in the eye and says, “It was easy.” How can you not love such overwrought and melodramatic prose?[/SPOILER]