The Borderlands Legendary Collection versions of Borderlands: Game of the Year Edition, Borderlands 2, and Borderlands: The Pre-Sequel come complete with loads of extra content, including the following major add-ons:

Borderlands: Game of the Year Edition
The Zombie Island of Dr. Ned
Mad Moxxi's Underdome Riot
The Secret Armory of General Knoxx
Claptrap's New Robot Revolution

Borderlands 2
Captain Scarlett and Her Pirate's Booty
Mr. Torgue's Campaign of Carnage
Sir Hammerlock's Big Game Hunt
Tiny Tina's Assault on Dragon Keep
Mechromancer Pack (play as Gaige)
Psycho Pack (play as Krieg)

Borderlands: The Pre-Sequel
Claptastic Voyage
The Holodome Onslaught
Baroness Pack (play as Aurelia)
Handsome Jack Doppelganger Pack (play as "Jack")