The English actor was in town to promote his latest flick I Give It A Year, which co-stars Rose Byrne.
"I love Dublin. It's a great city -- I can't get enough of it. You've got to love that Irish charm.
"I shot The F Word with Daniel Radcliffe, and Earthbound here. You have amazing actors in this country; I think Michael Fassbender is extraordinary."
And according to Dan Mazer, director of Spall's latest film, the charming Brit could rival Fassbender for the title of Hollywood's ultimate heart-throb.
In one of the film's standout scenes, Rafe and his co-star Rose Byrne (33), of Bridesmaids fame, appear naked.
Dan says ladies around the country are in for a treat. "I was incredibly impressed," he says.
I Give It A Year focuses on a newly-wed couple who have absolutely nothing in common.
It is being described as a "down and dirty version of Notting Hill" and is a lot more "com" than "rom".
So it's not surprising things got a little lewd on the set. The nude scene could have been uncomfortable to film, but Rafe found the perfect way to break the ice.
"I had to get naked in front of everyone," he says. "So to break the ice, I got my wife to take a picture of my naked body the night before.
"I sent it to the director and said "you're going to see it later, this is to let you know what you're in for'. It was a sneak peek."
Rafe is not your typical on-screen stud. In fact, most audiences are used to seeing him play losers, depressed writers or infuriatingly bad boyfriends with rubbish hair. Rafe admits that he had to undergo a bit of a make-over in order to play Rose Byrne's on screen husband, Josh.
"I got fitter for the role. I wanted to look my best so I cut my hair and lost a good bit of timber."
But Rafe says his inner dork wasn't completely gone. "He's the lead, but he's also got that dorky quality."
Rafe is married to former Hollyoaks actress Elize Du Toit and says his marriage helped him relate to his character Josh. "I could relate to my character because in real life I have a very beautiful wife who has no business being with me. I can relate to a man punching above his weight."
Director Dan is the brains behind Sacha Baron Cohen's many incarnations -- including Borat, Ali G and Bruno.
This explains the comedy's added edge. Dan says he was inspired to write the unconventional romantic comedy about a married couple who hate each other after witnessing several car-crash weddings.
"I've seen a lot of casualties, couples falling by the wayside. I wanted to pick up where all those other rom-com's left off."