Britney Spears: After a topsy-turvy first half of 2008, pop princess Britney Spears swept the MTV VMAs with a string of awards for her single "Piece of Me." Inspired by that success, she lambasted a male foe in the three-minute confection "Womanizer," which landed her back at #1 on the Billboard Hot 100.

Next, the freshly toned performer stepped into the Circus on her 27th birthday to launch her most successful album in more than five years. With a world tour cued up for 2009, global domination seems to be the name of Brit's game once again.

Check out daily updates on the singer at BritneySpears.com!

Robert Downey, Jr.: Not too long ago, there was a feeling that the next major news story on Chaplin actor Robert Downey, Jr. would be a report of his death. Downey had made headlines for everything from prison sentences to crawling into a neighbor's bed, all due to an unhealthy appetite for drugs. The 43-year-old actor quietly cleaned up his act a little more than three years ago, and now his acting is making all the noise.

Downey will remember 2008 as the year he rose above a string of at times inspired disappointments—such as Gothika, Kiss Kiss Bang Bang and Zodiac—with a pair of box-office gold performances in Tropic Thunder and Iron Man.  Having launched a franchise with his take on Marvel's classic, metallic hero, Robert's services are in the highest demand of his career.  Look for him alongside Jude Law and Rachel McAdams as the title detective in Guy Ritchie's Sherlock Holmes.

Tom Cruise: Remember the jumping up and down on Oprah's couch?  The huffy argument about psychiatric medications on the Today Show with Matt Lauer?  Two years ago, Tom Cruise seemed to have exiled himself into a ring of bad-image hell from which there is no return.

He began working himself back into Hollywood's and America's good graces this past August, sharing the accolades with Robert Downey Jr. in Tropic Thunder. For their over-the-top comedic turns in the satirical Vietnam-era action movie-within-a-movie, both 46-year-old Cruise and Downey received Golden Globe nods.

Tom's most serious repairs were to public perceptions of his character.  He revisited Oprah and addressed the jumping incident; he admitted to Matt Lauer that his views had been expressed arrogantly. And really, Mr. Cruise has nothing to be humble for.  Daughter Suri has been proclaimed the most powerful toddler in the universe; wife Katie is headlining a hit Broadway show.

Up next for Cruise is the WWII drama Valkyrie, out December 25. Reviews are mixed, but with Suri being so all-powerfully cute, Tom could probably weather a flop.

Mickey Rourke:  Like no other performer this year, Mickey Rourke has wrestled a career resurgence that is causing skeptics to overlook little things like politically incorrect commentary and sexual preference confusion.  All that controversy and madness suddenly seems to be part of the method to Rourke's tour de force acting triumph in The Wrestler.

The Darren Aronofsky-directed vehicle is a gut-wrenching (literally, at times) tale of a washed-up celebrity wrestler whose heyday is 20 years gone. While the broke-down Randy "The Ram" Robinson attempts to both make a connection with a local stripper (Marissa Tomei) and make amends with his estranged daughter (Evan Rachel Wood), it's hard at times to know if 52-year-old Rourke is playing a character, or himself.

Mickey snagged both Golden Globe and Independent Spirit Award nominations. There has been Oscar talk since the earliest screenings.  He'll next star in the big-screen adaptation of Bret Easton Ellis' book of short stories, The Informers, out May 1, 2009.

Let's hope 2009 will continue in banner-year mode for this resurgent foursome.

Who else has had a great year, and deserves more in the 365 days to come?