The Deterrent - Full Playthrough
Another one of the classic New Vegas quest mods, albeit a somewhat recently overhauled version.
That's fine though, because the changes are universally an improvement.
Some of the encounters are a *little* on the trolly side as you enter a room with 5 mutants in front of you with your back to a wall, but they're still do-able, even with a rebalance mod like Jsawyer.
(No promises with more extreme mods like Realistic Damage or Project Nevada.)
I also enjoy the thought (or at least, happy accident) put in to the structure of the Main quest and the optional exploration areas, minimizing the oh-so-frequent problem of the player wanting to intentionally go the "wrong way" while progressing through the story in order to not to miss any optional areas and secrets.