All eyes were on Colin Farrell when he first burst onto the American scene in Tigerland and American Outlaws, with many lauding him as the next super-star. Then he spoke! His interviews were laden with foul language and unabashed claims of bedding anyone and everyone in Hollywood. He also boasted of his love for the bottle. He quickly earned the title rebel, but he also turned off a big portion of film-goers... 
Well, the Irish-born actor is cleaning up his act. He entered rehab two year ago after realizing he would die, otherwise. He said:
"It was a fairly drunken life for 16 years so it was a tough life change, but I was dying and I'm one of the lucky ones in that so far I'm out of it...For me there was no choice. I was pretty sick. I went away for five or six weeks and that was a very safe environment and I began to come out of the haze that I had burrowed myself into so deeply... I came back into the world and everything was in a degree of focus that I hadn't experienced."
Although he had great success in Hollywood, had he been more focused and healthy, he'd be the biggest box-office star. His looks went south and it appeared he was headed toward Mickey Rourke territory. After nearly stealing Minority Report from Tom Cruise, the wonder boy followed it up with the turkeys Phone Booth, Daredevil and S.W.A.T.
It's not too late - Let's hope his future is lucid, lucrative and illustrious.
[Source]
His looks really are going south. That's what drugs and drink will do to you.