Michael Douglas as Billy
Robert De Niro as Paddy
Kevin Kline as Sam
Morgan Freeman as Archie
Mary Steenburgen as Diana
Jerry Ferrara as Todd
Romany Malco as Lonnie
Weronika Rosati as Veronica
Four old, old friends try to avoid going 'gently into that good night' (or at least not doing so alone) by hieing off to the city of a billion light bulbs—Las Vegas—and all the diversions it can muster, which amount to little more than hackneyed bits from a dozen other comedies about Las Vegas and old people.
Because it's Vegas, those other comedies are going to be bachelor party ones because that is the only reason anyone ever goes to Las Vegas. This bachelor party belongs to Billy (Douglas)—who believes either that life begins at 60 or it ends at 70, so either way, he'd better hurry up and get married for the first time—and his best friends from childhood who are desperately trying to get away from reminders of life in old age.
The big difference (okay, the only difference) between "Last Vegas" and the films it is—rip off is a dirty phrase, let's say 'is an homage to'—is that this one has a very well put together central cast which manages to pull off the material almost as often as they are trampled by it. Not so much because they've been given great characters to play as the freedom to play themselves (or at least the film types they most often portray) from De Niro's grumpy homebody to Kline's over exuberant retiree desperate to make use of the hall pass he has from his wife. Not everyone can pull it off—Douglas often seems to be reading from a cue card and gets left out of most of the gags—but they all seem so happy to be there you can almost give them a pass.
All the screen charisma and good will in the world can't help a script which seems cobbled together from bits and pieces of other similar plots: it would be easy to suggest watching "Last Vegas" is like looking into the future and watching "The Hangover 47," but that would insinuate a level of bite (or at least attempted bite) "Vegas" could only hope to achieve. Not every script has to have great dialogue or an intricate plot, entertainment comes in a variety of different flavors, just not any of the ones Dan Fogleman ("Crazy, Stupid, Love"). Instead, what we get is the feature film equivalent of a Chuck Lorre sitcom, with easy set ups followed by a feather bed landing to make sure we don't break a hip on our way down. It opens up a bit when Mary Steenburgen's torchy lounge singer shows up, but that's too close to writing something besides a cartoon and we can't have that.
By the time Billy's actual bachelor party has gotten under way, even the most neophyte of viewers will be able to describe exactly how the film's divergent plotlines will resolve themselves; and a story without surprise is a story without entertainment. Director Jon Turteltaub doesn't seem interested in doing more than string the set ups and payoffs together in as professional and uninspiring a manner as possible. Or maybe he realized early on there was no saving this script and the best he could provide was a good cast.
It's commendable for youth-obsessed Hollywood to make a film about mature characters; it's not to waste such a rare thing on clumsy jokes and a tepid plot. "Last Vegas" is the cinematic equivalent of a corpse flower, something so rare to see in bloom you want to convince yourself it's worth putting up with the stench of rotting flesh.