But none was more affected than his on-screen family, the sprawling cast of the "The Sopranos," many of whom paid tribute to their fallen friend in the hours after his death:
Lorraine Bracco - Dr. Jennifer Melfi
We lost a giant today. I am utterly heartbroken.
Edie Falco - Tony's wife Carmela Soprano:
I am shocked and devastated by Jim's passing. He was a man of tremendous depth and sensitivity, with a kindness and generosity beyond words. I consider myself very lucky to have spent 10 years as his close colleague. My heart goes out to his family. As those of us in his pretend one hold on to the memories of our intense and beautiful time together. The love between Tony and Carmela was one of the greatest I've ever known.
David Chase - Creator of "The Sopranos"
He was a genius. Anyone who saw him even in the smallest of his performances knows that. He is one of the greatest actors of this or any time. A great deal of that genius resided in those sad eyes. He was my partner. ... He was my brother in ways I can't explain and never will be able to explain.
Brad Grey - Producer of "The Sopranos}
Jimmy was one of the most talented, authentic and vulnerable actors of our time. He was unorthodox and truly special in so many ways. He had the sex appeal of Steve McQueen or Brando in his prime as well as the comedic genius of Jackie Gleason.
Michael Imperioli - Tony's protégé, Christopher Moltisanti:
Jimmy treated us all like family with a generosity, loyalty and compassion that is rare in this world. Working with him was a pleasure and a privilege. I will be forever grateful having had a friend the likes of Jimmy.
Dominic Chianese - Tony's mentor, Corrado "Junior" Soprano, Jr.:
I never had an actor work so hard physically. His input to that show was critical to its success. It was incredible. He had to live that part for 10 years. He had stay connected into the role. Just learning all of the lines was an incredible feat. I think he only missed work one day in 10 years. He made it believable, every single scene.
He was in almost every scene, and that’s an incredible amount of work. You have to go home and do your homework. He was so young. In fact, he was just a kid when he started…you needed to be young to be able to handle that load.”
The only image I had was standing and watching him, like watching the water flow. He was that easy, that focused, that real. It wasn’t like we were acting.
Steven Van Zandt - Tony's adviser, Silvio Dante:
I have lost a brother and a best friend. The world has lost one of the greatest actors of all time.
Tony Sirico - Crime family underboss Paulie "Walnuts" Gualtieri:
From the day I met him on ‘The Sopranos’ we became friends and family. We travelled to Iraq and Afghanistan together, me, Jimmy, and my pal Mike Sullivan. We visited base camps, field hospitals, talked to the troops. Jimmy would tell the soldiers he wanted their autographs, that they were the heroes. They were the stars.
David Proval - Tony's brother-in-law, Richard Aprile, Sr.:
I couldn’t have asked for any better actor or better gentleman to work with. His generosity was unmatched. He was always right there for me during the show. It was a head-spinning experience for everyone, yet he always found the time for me and everyone on the cast.
John Ventimiglia - Restauranteur Artie Bucco:
My heart is broken and my heart goes out to his family and his children. He was one of the most generous and supportive people I’ve ever known. I looked up to Jim. He inspired me. Right now it’s just hard to imagine a world without Jim in it.
Steve Schirripa - Tony's brother-in-law, Bobby Bacala:
The guy was like a brother to me. He was a great actor, a great father and was a lot of laughs. This is devastating. When I say we were like family, this is very much like losing a family member.
Frank Vincent - Rival mobster Phil Leotardo:
We were enemies on screen, but pretty good friends off screen. Jim was a loving guy who just enjoyed life. It’s a sad and tragic thing that’s happened. I feel bad for his family.
The restaurant where the famous final scene of the show was filmed offered their own quiet, moving tribute.
By Christian9Klein on Instagram
Notable deaths of 2014 [PHOTOS]