The guys - Alec Baldwin, Jim Carrey, Zach Galifianakis, Robin Williams
The gals - Tina Fey, Amy Poehler, Betty White
I think these comedians represent a good part of the humor style spectrum, ranging from goofy to witty spiced with some crass, with their own idiosyncratic inflections. The guys tend to be either suave (witty) or slapstick (goofy), or both (Robin Williams seems to do both pretty well). The gals are mostly clever (witty) and sometimes goofy, but in a different way than the guys. Somehow it's more acceptable for guys to flaunt themselves than for gals... hmm.
Granted, their style has a lot to do with their native personalities. Whereas Baldwin fits nicely in a boardroom or 007-type scene, I cannot picture him in a tutu (i.e. Carrey's Black Swan parody) or entertaining pre-schoolers (i.e. Galifianakis). Williams is more of a chameleon in this sense because he acts out the "fool" archetype much of the time but also being serious simultaneously, i.e. Mrs. Doubtfire, Patch Adams, etc.
The gals tend to stay true to how they are in real life, I think. We have a self-deprecating geek, an in-your-face no-nonsense go-getter, and a mild-yet-snarky grandma. Their gigs mostly center on these character types and it's difficult to imagine them playing something else. Fey's style is somewhat similar to Galifianakis' in that they often make fun of themselves. I find this rather endearing (probably many people too). This is in part due to my cultural upbringing, but I must say it's the safest strategy in this contemporary atmosphere that is super-charged with political-correctness.
Tangentially related... the Comedian from Watchmen is not funny "hahaha", but funny "I'm gonna make your life a joke". See how this archetype works better in a guy?