4. Amy Poehler
Although Tina Fey may arguably be a better choice, she's pretty much ruled herself out. However, Amy Poehler would be every bit as capable of handling the job. She has many of the same qualifications as Seth Meyers (SNL, Weekend Update, etc) but has one distinct advantage over Meyers. She has much more experience with improvisation. While both got their start in improv troupes, Poehler has done considerably more of it, and was also much more successful with it. Of course, she's currently attached to another NBC property - Parks and Recreation - but with continually lowering viewership numbers, the show may not last until 2014 (which is when Fallon is scheduled to leave). If we must lose Parks and Rec, at least we have the hope of Poehler getting the Late Night chair.