I am having trouble figuring out the best way to end my novel... Essentially, the issue is "do I kill off my characters or nah?" What would you recommend? One guy is about to prepare himself for jumping off a bridge and into the river when another guy stops him. They talk and some life bombs are dropped. When the second guy accidentally falls off, instead, the first guy leaps after him and both manage to survive. They continue the conversation in the hospital (after decent recovery) and the first guy isn't sure how to be grateful to have his life when the second guy ended up "much worse" (from the near-drowning). And then I suppose his narrative would close with him accepting that he has more to learn in his life or whatnot. The first half of the first scenario plays, except the second guy didn't get there in time to prevent the first guy from drinking (which he figured would prevent him from swimming back to the surface during his attempt). So when the second guy drops, the first guy goes after him, but due to the alcohol content in his system, he dies and therefore the second guy dies as well. The themes the reader is supposed to learn or whatnot would then be picked up by the surviving characters, with a larger emphasis on death and grief and struggling to understand/accept what has happened. Which scenario would be more satisfying/tie up a novel better/be the most realistic, based on just what I have told you?
Though I don't really have the best handle on the situation just from what you've described, I think the important thing is this: To paraphrase Dwight Swain, readers need to feel like the main character 'earned' his ending, whatever that may be. They want to feel as though his direct actions led to the direct consequences described in the ending. So rather than "pick" the ending based on what it is, I'd advice you to choose the ending based on what you feel your MC earned.
I don't think a character has to die for things to have a bigger impact on the character. As long as the writing is honest the effect will be the same on the reader. I personally like the first one better, because it feels less like I'm being thought something, and am allowed to judge for myself how this makes me feel. I like that the other guy is more hurt the the first one though. Hope that helps