After almost five years of calm, the late night TV grid is going through some pretty radical changes, first with Jimmy Fallon taking over for Conan O'Brien in NBC's 12:30 slot. Next up, in a week and a day, Conan snags the storied "Tonight Show" chair from Jay Leno.

Not only will that move end a much-hyped 16-year rivalry between Leno and David Letterman, it also facilitates a controversial shift Jay makes to 10 o'clock that may well end network television as we know it.

It's some historic stuff, making now as good a time as any to pick your favorite among the late-night gabbers.

After the jump, we weigh the strengths and weaknesses of the guys who have to do it an hour a night, four times a week.

Jay Leno

Strength: Even his critics would concede Jay's show is professionally done, and always fairly watchable. The best opening monologist on network TV.

Weakness: As the go-to-guy for the entertainment-industrial complex, he tends to get the best guests. Being the go-to-guy for said complex, nothing too interesting happens when they appear.

David Letterman

Strength: Letterman may be an odd duck, but he has also always been more like a person than most chat-show jockeys. If a late-night guest does something noteworthy, it almost always happens on Letterman, and perhaps it's Dave's warts-and-all humanity that brings out the whack.

Weakness: Wildly inconsistent, he's been mailing in segments, and sometimes entire shows, for years.

Jimmy Kimmel

Strength: He has an easy, if not necessarily smooth, way about him that lends itself to the chair behind the desk. The show has produced its share of viral-worthy moments. (Often featuring Matt Damon.)

Weakness: Can't get beyond the fact that the world would be funnier place if Adam Corolla -- Kimmel's old "Man Show" co-conspirator -- had gotten an hour on network TV instead.

Conan O'Brien

Strength: Conan cut his comedic teeth as a writer for the Harvard Lampoon and "The Simpsons," and has done an admirable job of bringing that brand of silly/smart to late night TV.

Weakness: His self-effacing jokes about being creepy and awkward work so well because he sometimes is creepy and awkward. And that can be a little hard to watch.

Craig Ferguson

Strength: While it's true we've seen less of Ferguson than the other four -- being he's the newest kid on the block and comes on the latest -- every time we flip to the quick-thinking Scot he's hilarious. A natural's natural.

Weakness: Tends to be overly self-referential. Still, this guy needs to take over for Letterman when Dave hangs it up.

Jimmy Fallon

Beyond our initial surprise that he landed such a gig, we haven't seen him enough to form an opinion -- but we'd love to hear what you think of Fallon, or any of the late-night gang, in the comments section.