The game's half a decade old, this shouldn't be considered spoiler territory. But for those who just got it free from PS or whatever:
At least until Phantom Liberty, all roads lead to assaulting Arasaka Tower to get to Mikoshi, and everyone doesn't walk out of there alive.
(Always available) You can always just commit suicide and not risk anyone else's life. The ending is just people pissed at you over the phone, but you don't take anyone down with you.
(Always available) Side with Hanako to take out her brother. Clearly portrayed as the bad ending, as the Arasakas' grip on Night City tightens. They have no interest in keeping Johnny alive, and their surgeries don't work on V either, and you either get engramed yourself or go back to your old life for what little time you have left.
If you've done enough side missions, there are additional options to either get either Rogue or Panam's help in assaulting the tower. However, only one of Johnny or V can keep the body.
Rogue: Assault the tower from the top. If Johnny gets the body, he leaves town peacefully. If V gets the body, you keep rising up the merc ranks with the time you have left.
Panam: Assault the tower from underground. Johnny's ending is the same if he gets the body, but if V keeps the body, you and the Aldecaldos leave town.
Secret Ending: If you've chosen specific chat options over the course of the game, Johnny says "Fuck it, let's do it ourselves", and you two will assault the tower through the front door. You're still left with the same Johnny leaves town or V keeps mercing options once you hit Mikoshi, however.
Phantom Liberty: With the expansion, if you side with Reed, and you can keep Songbird alive, the NUSA will manage to keep V alive. But the ending is pretty disappointing, as the game catches up years later and effectively yells at you for not leaving a pretty corpse, and Militech takes over Night City.
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Obviously, those endings are going to be messy to align to one common ending with the sequel in 2080 (or whatever). Guessing the Militech invasion of Night City happens in 2078/2079 regardless, with a new Arasaka (probably Michiko) in charge when the sequel starts, with some minor comments depending on the player's choices in the original.