Original: He is best-known for his role of Santino 'Sonny' Corleone in 1972's The Godfather, Paul Sheldon in Stephen King's Misery, 'Big' Ed Deline  in Las Vegas and for his role as Will Ferrell's father in Elf.
Simplified: He is known for his role of Sonny Corleone in 1972's The Godfather and for his role as Ed Deline on Las Vegas.