Cruise got $100 million for Mission Impossible 3. That was before he went crazy, granted. But still: $100 million! He’s obviously done something right over the past couple of decades to put himself in that position.
Rather ironic, considering that he was the original shark jumper. 
Because in the entertainment industry, a TV star is regarded as a second class citizen when compared to a movie star. Movie star fame is considered more substantial and long-term than TV star fame which is like flash powder–it’s hot and intense but only lasts for a short period of time (i.e., until the TV show ends).
Shelley Long still gets a lot of flack for leaving “Cheers” after five years but I think that even if she’d stuck around until the series ended, her career would still be at where it is now.
It took quite a few years for Michael Jackson’s eccentricity-later-outright-nuttiness to negatively impact his marketability. In fact, you could argue that it never really did; changing public tastes and the declining quality of his output did.
Give Tom a few years to really fuck it up. 
Cruise is an absolute A++ list star, though, one of the biggest box office draws who has ever lived. In terms of popularity and influence, he has literally nowhere to go but down, anyway.
I also wonder, really, how much damage he’s supposedly done. I mean, I don’t care about his personal life. If he was a murderer or a child molester perhaps I would, but he’s just kind of weird. Do you know anyone who really gives a shit? I don’t.
For best managed career I wholeheartedly agree with the nomination of Arnold Schwartzenegger; I think he has to be the all time champion in this category. 30 years ago, the only human being in the universe who would have predicted that one of the world’s most popular and marketable movie stars would soon be a roid-laced muscleman with an Austrian accent who couldn’t really act was - Arnold Schwartzenegger.
Going back, the classic example of poor career management is George Raft. He was signed to be a major star at Warner’s, but turned down High Sierra because he didn’t want to play a gangster who died in the end, and later turned down The Maltese Falcon because he didn’t want to work with a first-time director. Humphrey Bogart took both roles and became a major star. Raft was also suggested for Casablanca, but Bogart had already been given the part.
Bela Lugosi made some horrible choices toward the end of his career, though his drug problems probably caused work to dry up.
Carrie Snodgress made the mistake of giving up her (quite successful) acting career to be Neil Young’s girlfriend. Despite being considered one of the top new actresses of 1970 (with an Oscar nomination and a Golden Globe win), she vanished from the screen for eight years and was doing TV guest shots instead of leads.
Just on the first point about Valerie Harper, I wouldn’t have said she “jumped ship”. Within the same MTM “family” she was “spun off” and went off to five seasons (according to IMDb) of Rhoda.
Sally Struthers never should have left All in the Family. I know that Reiner wanted off to, but she should have volunteered to play Gloria’s long lost twin who returns home or something in order to stay. She’s never come anywhere near that and regrettably she’s become something of a joke.
Corbin Bernsen was a TV superstar when on L.A. Law but he flatlined and fast. Before it even left the air he was doing majorly stupid movies about frozen sperm and now he has supporting roles in cheesy made for cable movies. Harry Hamlin and Susan Dey should have talked to McLean and Shelley and Sally before leaving L.A. Law (though Susan Dey left for another series that probably made her a really great deal).
Shannon Doherty is an actress who like Michael Jackson or Anna Nicole would be locked inside an observed and padded room were she not in L.A. and making enough money for keepers. She can’t seem to keep a series and she has one of the worst reputations in show business as far as personality and reliability to go. Of course it has to really suck hard [no pun intended] knowing that your husband and Paris Hilton made a porn movie together.
Carson Daly was caught on film pledging his soul to Satan for the success he’s had. I’ve said it before and will here that of all the people in Hollywood who have careers his is the one I probably understand the least. He’s stupid, ignorant and only marginally cute and Rin Tin Tin would have been his equal at the interview. Get his manager if you can. (Ryan Seacrest, who though I personally am near nauseated by him is cute at least, seems to understand the Arthur Godfrey/Norma Desmond nature of fame and is raking in every penny he can while he’s hot, which I respect totally.)
Lisa Bonet first erred by pissing off Bill Cosby to do graphic sex scenes while on his ultra-family friendly sitcom, then ever since she’s just gotten progressively weirder. Last I heard she was on an interview program talking about how she’ll never let her child (by Lenny Kravitz) be immunized because in her considerable medical expertise she’s against vaccinations of any kind.
Jasmine Guy and Neil Patrick Harris are two fairly big TV stars that I believe went to stage so they didn’t disappear entirely, but the rest of Different World, 90210 and Head of the Class and other teen heartthrob shows casts seem to have joined a cult.
There are lots of talented aging-young stars that have never really hit the bigtime: Alicia Silverstone (she works but she’s definitely B-List), Skeet Ulrich, Wes Bentley (huge buzz for American Beauty then just sort of lay there,
LOTS and LOTS of soap opera actors quit the day job and end up doing infomercials or walk ons on low rated sitcoms if they’re lucky.
My winner for mismanaged male career is Seth Green. The guy was sizzling hot after the first Austin Powers movie and he comes across as very bright on interview shows. I’m surprised that he’s still stuck in B and C list projects and voiceovers (even if it is for a hit show) when he had the talent and the following to get either starring roles in B list movies (better than the teen comedies he does) or supporting roles in A list movies. (BTW, he majorly pings my gaydar whenever he’s interviewed on a talkshow- does anybody know?)
George Lazenby who was the first Bond after Connery decided to not continue the Bond series. Bad for him, good for Roger Moore. His acting career never really flourished after that although he managed to get rich in real estate so I guess he’s okay.
Are we focusing on actors, because former athletes (like Mike Tyson) and musicians (like MC Hammer) whose later lives resemble train wrecks would fill a thread ten pages long.
Guy’s done okay on the cable show Dead Like Me and Harris, in addition to the amusing but short-lived Star Raving Mad was for a time the animated voice of Spider-Man, which I think is kinda cool.
I saw Wil Wheaton not long ago on an episode of CSI playing a deranged barely-recognizable homeless guy, which feels vaguely prescient for some reason. Time will tell. He’s been the cartoon voice of Aqualad, who is about fifteen orders of magnitude less cool than Spider-Man.
What, am I the only one here who loves How I Met Your Mother?
Neil Patrick Harris is back on top in How I Met Your Mother.
Buster Keaton. (I can’t believe I didn’t think of him before.) Keaton was a major star until his agent told him he should go work for MGM (the agent’s brother was an executive there). Despite the advice of all of his friends, Keaton followed the agent’s advice, lost control of his films and was so washed up that his appearance in Sunset Boulevard was something of a sick joke.
Paul McGuinness, manager of U2. He’s been with them since the beginning, they’ve only had one concert where a band member didn’t show up, he’s got them set up with multiple corporations and holding companies and what not, and has figured out to get them tons of exposure while avoiding the label of “sellout” (i.e., the U2 iPod that they didn’t get any money for, the current FIFA World Cup ads, that they didn’t get any money for).
OP speaking: musicians are fine; athletes too, I 'spose, though being a great big nerd I have naught to contribute to a discussion about them. What about Tyson? I know he doesn’t play basketball anymore, but doesn’t he have a behind-the-scenes role for the Bulls or something?
Jordan?
::googling::
Okay. Gotcha. Jordan’s the basketball player, Tyson’s the boxer or whatever.
Even funnier is that Jordan’s life is a stellar example of good management. When he was pulling down $4 million a year, his manager put him on an allowance and Jordan’s personal discipline (as well as the positive influence of his mother) kept him from going hog-wild and ending up with a drug habit.
I get the impression he does Rayovac commercials just to keep his hand in the acting game while waiting for Space Jam 2, taking the occasional vacation to count his money.
Well he is the co-owner of the Charlotte Bobcats, as well as several other notable business ventures, so he’s doing a bit more than counting his money.
Having just read the wikipedia on Mike TYSON, I may add …
damn.