Welcome to the "80 Over 80,"Slate's annual list of the nation's silver lions: fourscore elder statesmen, business leaders, cultural icons, and notorious newsmakers who have each remained influential into their ninth decade and beyond.   As always, we've ranked these still-twinkling stars according to their power and importance, with extra credit given for energetic achievements post-80 and for being really, really, really old.

The top spot this year goes to 82-year-old Thomas S. Monson, president of the Church of Jesus Christ of Latter-day Saints, and the only person on the list to rule over millions of people as a prophet of God. Enjoy it while you can, Monson—you're only old once.

Last year's top geezer, John Paul Stevens, slides down to No. 2 amid rumors of his imminent retirement from the Supreme Court, while Barbara Walters—a "79er to watch" from last year—debuts at No. 4. The top 10 includes a few more fresh old faces: Noam Chomsky and Gordon Moore, both just 80, make impressive showings in their rookie campaigns.

Last year's political upheaval propelled several congressmen up through the rankings. The 85-year-old Hawaiian Daniel Inouye leaps to No. 3 after gaining control of the powerful Senate appropriations committee. His predecessor and fellow Democrat Robert Byrd dropped to No. 10. (It could have been worse: A lingering staph infection nearly landed Byrd on this year's "Just Missed" list along with Paul Newman and William Safire.) Meanwhile, former committee chairman and disgraced Alaska Sen. Ted Stevens made an ignominious departure from the list.

The recession took its toll on our wealthiest octogenarians. Media magnate Sumner Redstone lost $3 billion and dropped 34 spots in the rankings. Kirk Kerkorian went $11 billion in the red and fell out of the top 10. And midlist stalwart Alan Greenspan, whose laissez-faire economics helped precipitate the market collapse, was demoted to the bottom spot, No. 80.

Expect more shake-ups in the coming year. We've got an extraordinary selection of 79ers to watch, including billionaires Warren Buffett and George Soros, as well as a very fit Clint Eastwood. Will one of these geezers unseat the Mormon prophet in 2010? Turn up your TV as loud as you can, people. It's going to be an exciting year.

Read the text-only "80 Over 80" here.

Corrections, Oct. 21, 2009: The original version of the gallery of honorees inadvertently showed a photograph of Mormon Apostle Neil Andersen in place of church President Thomas S. Monson. Also, it listed Joe Paterno as having won only one national championship instead of two.