The Boatman's Dog - The Boatman's Dog serves the finest cuisine. Much finer than an establishment of it's stature should be serving. At "The Dog" the fire is always crackling and the ale is always cold, but guests go missing, and no one is sure where the charismatic halfling proprietor Angus Thickheel is getting his meat.
The Crumbling Wall - A mysterious bard sits atop a crumbling wall deep in the forest. What secrets are told in his sonorous tunes?
Gregorio's Traveling Emporium and Managerie- Gregorio is a traveling merchant, with a "magnificent" menagerie and a dark secret.
Each of these encounters is short, creative, and has a nice sense of mystery and dread. They're all low level encounters and be great if you want to play Curse of Strahd but not use Death House as your intro. If you go that route, I'd start with The Crumbling Wall.