4. Robert De Niro
It's entirely possible that De Niro simply set the bar too high, and the weight of trying to constantly outdo his own flawless, legendary performances became too much of a burden. And to be fair, very few actors can say they put so much of themselves into their roles. (The Leos and Tildas and Daniel Days of the world can relate, but no one else could likely fathom it.) Besides, not every script he receives is going to be a winner. And maybe that pile of meaty roles, once written especially for him, have stopped piling up on his agent's desk, and are now going to other "Robert De Niro types." How much of that is his own fault and how much is due to the natural progression of time and the harsh march of aging is still up for debate, but one thing is not: Regardless of why it happened, De Niro rarely bothers showing up for his roles anymore, choosing instead to sleepwalk through 90 percent of his screen time. A definite turning point occurred in 2002. De Niro had just shown up in Analyze That, the sequel to the comedy that asked him to essentially lampoon his own tough guy, mobster schtick. The first installment was fine enough, if not particularly groundbreaking...but a sequel? For shame, Robert. By the time he made Meet the Fockers in 2004, his credibility was pretty much shot, as was his desire to give an inspired performance. (And then he also went ahead and made Little Fockers, just in case there was any confusion as to whether he had officially given up.)