Movies of his that stood out..

The Godfather AND TV movie tearjerker Brian's Song in 1972
Godfather Part II (he's only in it for a few minutes at the end, in a flashback, but the audience applauded when he first appeared on screen -- his macho had been MISSED)
Slither(weird, a lot of fun)
The Gambler (playing a college professor?!!)
Freebie and the Bean (totally un-PC, a BIG hit, hilarious car chases, Caan and Arkin are hilarious together and Alex "Moe Greene" Rocco does a short bit as a crazed SF DA.)
Rollerball(the original -- macho, macho, macho)
Funny Lady(singing and dancing with Babs)
The Killer Elite(for Peckinpah -- director and star were coked up but its a wild ride, and The Consigliere Robert Duvall was along for it.)
Harry and Walter Go to New York(Gould and Caan -- a "young Jewish star buddy team is born" -- but so were Caan and Arkin. Michael Caine and Kay Corleone(Diane Keaton) join them.
A Bridge Too Far(with 30 some other big stars...but Caan gets the most emotional episode.)
..and other seventies movies

Came the 80's, Caan opened strong with:

Hide In Plain Sight (Caan directed this suspenseful "based on a true story" piece about a divorced man whose wife disappears with their kids and a new Mafia dad into witness protection.)
Thief (Michael Mann introduces his color scheme and Tangerine Dream -- Caan kills as a pro on one last job...)

And then, slowly at first...but suddenly pretty quickly...Caan's star career collapsed. Drugs and bad work habits, they said. His dear sister died young of cancer an that put him way down emotionally.

There are other 80's movies for Caan(one for Godfather director Francis Coppola) but it took until 1990 and one ironic movie to bring him back:

Misery. As a crippled man trapped in a bed and tortured by a psychotic fan (Kathy Bates.) Caan, almost forgotten, only got the role because most of the male stars in Hollywood had turned it down. It gave Caan a comeback and a long later career in character parts.