Nothing kills a love story quicker than actors with no chemistry. (Ah, remember the debacle that was Julia Roberts and Nick Nolte in “I Love Trouble”?)

On the other hand, a movie like “The Adjustment Bureau” — where the characters’ intense romantic connection drives the plot — soars because of the actors’ palpable chemistry.

Matt Damon and Emily Blunt work so well together that they even turn their meet-cute scene into something special. On election eve, Damon’s wannabe senator is rehearsing his concession speech in the empty men’s room in a fancy hotel before he has to face his disappointed supporters. Well, he thinks it’s empty. He hears something in one of the stalls. Out comes Blunt, explaining she was hiding from security after she crashed a wedding in another part of the building.

Stupid, right?

And the characters could easily be caricatures. Damon’s an ambitious politician who’s got a (sometimes sublimated) wild streak. Blunt’s a dancer who’s a free spirit. She crashes weddings! She drops Damon’s cell phone in his coffee so he won’t answer it — oh, how wild and crazy!

Blunt uses her intelligence, wit and warmth to create a rich character from what would — in the hands of a lesser actress — be a saving-a-man-with-her-untamed-spirit stereotype. Blunt punctuates the flirty dialogue with a raucous laugh, and Damon responds in kind, loosening up whenever Blunt comes onscreen.They form a fun, emotional, adult relationship.

Because their connection is so passionate, the whole notion that their characters literally fight fate to be together makes absolute sense.

Who are your favorite examples of actors with the most — and least — romantic chemistry?