This 2010 movie worked its way to the top of the Netflix queue. Not bad: a screwball comedy set in the world of professional killing. You kind of have to turn off your moral sense to enjoy it.
The hero here is Victor Maynard, played by Bill Nighy. Victor is well-known inside the community as the best in the business, but he's actually just continuing the family trade with colorless, dispassionate efficiency. His mother, put away in an old-folks' home, approves of his profession, but why hasn't he gotten married? It's obvious to anyone who's watched over fifteen minutes of Dr. Phil: Victor is emotionally shut down.
But all that changes! Of course. It's brought on by Rose, a small-time free spirit, thief, and con artist. We like her too, because she's played by Emily Blunt, full of charm, good looks, and wit. She has hatched a big score, duping a customer into thinking he's buying a stolen Rembrandt; instead, Rose sticks him with a well-done forgery. Unfortunately for Rose, the trick is quickly discovered. Worse still, the customer is not the kind of guy to go to the cops; instead he calls up Victor to terminate Rose with extreme prejudice.
Which is initially OK with Victor, but a series of missed/bungled opportunities puts him into too-close familiarity with Rose, and he—literally—finds he can't pull the trigger. This puts a target on the back of both Rose and Victor. What will happen? I bet you can guess. But it's fun watching.
Rupert Grint, yes Ron Weasley himself, plays Tony, a stoner to whom Rose and Victor get attached in their travels. Also notable is Martin Freeman (who played Watson to Benedict Cumberbatch's Sherlock in the great BBC series) as the "bad" hitman who's hired to eliminate the good guys.