I've heard really great things about the Freeport adventures and I have the Pathfinder copy of the setting that I need to dive into.
Rise of the Runelords and Curse of the Crimson Throne have both been published as hardback adventures, and very easy to get ahold of. If you play with minis, the pathfinder pawns for these campaigns have 75% of the minis you need for bad dudes. I ran my group through a regular game of RotR, and I started to feel DM fatigue midway through chapter three after running the game for about two years and 30ish sessions. If you run this, I'd skip most of chapter two and go straight to chapter three and beyond.
The I've been running Iron Gods in Eberron for the past year, and it's been a blast. We're about 20 sessions into it, and I'm concluding chapter two very soon. After that, I'm going to be homebrewing my own adventures.
If you're looking at old adventures, and want to cherry pick a dungeon or two, I would check out Tales from the Yawning Portal. WotC collected a ton of old adventures into it and revised them for 5e. Of note, it also includes Dead in Thay, which is a huge megadungeon and could easily be segmented and adapted for your own game. Tomb of Horrors isn't as great IMO to play through in 5e, but my group can at least say they did it.