Ravenloft is good, regardless of the edition, I have found. The expansion and detailing of the surrounding areas was just topping to already sumptuous cake.
Mines of Phandelver wowed me for hitting all the right notes for a D&D adventure - intro dungeon/fight, overland travel, wilderness encounters, unusual NPC interactions and some well-planned and stocked dungeons. It just felt “right”.
I’ve played in the old U1-U3 series and ran Ghosts of Saltmarsh, and enjoyed it a great deal. There’s a lot of mystery and thinking in this adventure, and it isn’t something you can just hack your way through (Well, at least until you figure out what’s REALLY going on). It has one rough spot (the U2 section), but that’s only because an on-the-ball party might figure things out extremely quickly and trivialize that section (but still have plenty of diplomatic things to do).
I wanted to put in a vote for Lost City, but alas I haven’t had the chance to actually run it in 5E, and my attempt to run it back in the ‘80s didn’t pan out because I didn’t understand that it was much, much more than a mere dungeon delve - it was a living ecosystem/world in a dungeon environment.
Lastly, I wish I could give good marks to Tomb of Annihilation, but the DM I’ve been bearing it under has made mincemeat of its contents and its been utterly underwhelming. I don’t even know what elements we’ve been going through are parts of the module and what aren’t - and I’ve refrained from reading it as its an active game for me.