This is Adam Sandler's first (that I've seen at least) purely dramatic role and he nailed it.
Sandler plays Dr. Charlie Fineman a former dentist who lost his wife and three young girls in one of the hijacked planes of 9/11. He suffers from post-traumatic syndrome and if not for the life insurance and legal settlements, his character would likely be homeless.
Don Cheadle, also excellent in his role as Dr. Alan Johnson, plays a wealthy dentist and former college roommate of Charlie's. They bump into each other on the street and Charlie doesn't recognize Alan due to his protective blocking of all things past.
Alan persists having read of Charlie's loss years back and is compelled to reach out to Charlie and "fix" him. This is in no small part an expression of his need to break out his own mid-life crisis and stagnation in his marriage.
Of note: Liv Tyler is an apt choice as Charlie's therapist and Jada Pinkett Smith (married to Will Smith) plays Johnson's wife.
Reign Over Me is a longish but well-made and moving film. A tale of two men who reconnect and wind up fixing each other. A must-see for Adam Sandler fans and a great couples night movie.