I had a really good experience with “DDEX-11- Defiance in Phlan”, especially with Mission 1 (The Meeting at Deepnight).
This basically an 0,5-1-hour long (“short”?) session about a meeting which goes wrong.
However, as it is obvious for the players, it sounds too easy, they might try to make plans, do their own investigation and so on. The meeting can be handled in multiple ways (fight is optional), hence all type of players can find their favored elements in this game and it is just long enough to figure out, whether this is the right hobby for them.
As for one-shots, I had so many great nights at Spielbar (from @gridshadow’s time travelling games, through @H’s annual “ACTION!”-sessions, @irx’s Jenga-based time-warping mysteries, @Simon’s “on-the-spot-improvised-one-shots” and from all the other great DM’s who dropped by to Spielbar to run a game), it is almost impossible to choose one.
However, if I have to take a 5e-one-shot, then I’d go with @Darthbinks’s roman/greek-era game
(I don’t want to provide more info to avoid spoilers - but that was very well crafted session with a very witty underlying theme).