Robert DeNiro is widely regarded as one of the greatest – perhaps the greatest – living film actor.

Certainly, he has enjoyed a spectacular career spanning more than four decades and has crafted some of the most compelling and unforgettable movie characters ever seen on the silver screen – from the mentally unstable Johnny Boy on “Mean Streets” to the cold, calculating young Vito Corleone in “Godfather Part II” to the psychotic “Taxi Driver” Travis Bickle to the brutish unredeemable boxer Jake LaMotta in “Raging Bull” to many others.

However, what exactly has DeNiro really accomplished in the last fifteen years?

This so-called “acting legend” has not made a decent film since “Casino” in 1995, nor a truly great movie since “Goodfellas” from two decades ago.

Is DeNiro so venerated and, if you’ll pardon the term, “untouchable,” that he remains above criticism?

He is currently appearing in a film called “Little Fockers” with comedian Ben Stiller, the sequel to “Meet the Fockers” (which, by the way, is the highest0grossing film of DeNiro’s career up to this point, excluding the second Godfather).

The next biggest-grossing DeNiro-starred vehicle? Another lame “comedy” called “Meet the Parents.” File that under “no accounting for taste.”

Granted, every great actor has appeared in many clunkers for a variety of reasons (namely money or desperation for an acting job). Marlon Brando (universally considered the greatest American film actor in history) himself appeared in several dreadful films.

However, DeNiro’s resume seems awfully overloaded with too many lousy films for someone of his “impeccable” reputation.

There has been scuttlebutt that DeNiro appears in films that are beneath his normal high standards simply so he can earn enough money to finance and direct more personal and artistic films at his own studio.

Fair enough, but aside from the excellent “Bronx Tale,” what other worthwhile projects has he been involved with on an independent basis?

I should clarify that I do indeed think DeNiro was a great actor at one time – but his fame and celebrity have become so massive and global that he no longer has a motivation or need to even be a “real actor” anymore. Hence, the endless appearances in truly crummy worthless films.

He is “overrated” in my opinion in the sense that his acclaim exceeds the true value of his output.

(I have heard DeNiro will soon reunite with his old partner Martin Scorsese in a film about an Irish gangster who reputedly killed Jimmy Hoffa. I hope and pray this will be a great film and thus partially restores DeNiro’s credibility.)

I think an analogy can be made to someone like Paul McCartney, the ex-Beatle who simply refuses to retire even though his talent abandoned him decades ago and who pathetically tries to remain “relevant.”

McCartney has released perhaps four dozen albums since The Beatles broke up, with each record sounding worse than the prior one. He cannot ever hope to reach the Olympian heights he scaled while a member of the greatest pop group in history – it must be terrible to keep having to compete against one’s own accomplishments from the distant past.

Even though film acting and rock-and-roll are quite different endeavors, McCartney (like DeNiro) is such a huge figure in his field that virtually anything he attaches his name to is guaranteed to generate enormous publicity (regardless of the quality of the underlying material).

Of course, McCartney and DeNiro are not alone in these futile pursuits. Huge paychecks and the chance to again be in the public eye are hard to resist – especially if one has become accustomed to being a “star” for all of one’s adult life.

Still, there’s something unspeakably sad about once great artists who will not gracefully retire – and who risk permanently damaging their legacies.