The closest I can think of was the Broken Sword had a section set in the West of Ireland or that section in Second Life. What sort of game would work best for Dublin? A street racer like Metropolis Street Racer/Project Gotham would be neat, so would a sandbox game but those can be massive to make.
A while back I had this post apocalyptic idea where Dublin is burried under a huge layer of snow and ice, and the game would involve you travelling down in ice tunnels to explore the remenants of Dublin in the style of FPS.
this is really strange, but the other day on youtube, the banner advert was for infamous 2 and some small print(the kind like on a beer advert where it would read "drink responsibly") and it said "this game is not set in Dublin".