Love Me Tender. This Civil War saga is about one woman who loved two brothers -- first Vance, and then, after Vance was presumed dead in battle, his kid brother, Clint (portrayed by Guess Who in his movie debut). When Vance comes home, the love triangle nearly destroys the family. The brothers end up realizing how strong their bond is, fortunately before one of them dies doing the right thing in a subplot about stolen money. I won't be a spoiler and say which brother dies, but he does ascend to heaven with his guitar. I know Toby Macguire and Jake Gyllenhaal did a movie that had basically the same plot with the Afghanistan war as a back drop, but it couldn't possibly be as impossibly, CinemaScopically glorious.
The Godfather, Part 2. "I'm your older brother, Mike, and I was passed over!" and "I know it was you. Fredo, you broke my heart." Those Corleone boys gave one another an operatic level of grief.