I run a bunch, mostly focused on making the game closer to DND 5E where possible, expanding build options, somewhat more difficult and tactical, and more immersive generally. I've been very happy so far.
- Additional Fighting Styles
- Bard Fixes and Tweaks
- Cunning Strike and Swashbuckler
- Eldritch Adept
- Fighting Initiate
- Tactician Plus (a lot of these mods do make the player more powerful, so this helps even it out a bit to keep the challenge relevant)
- Choose Your Stats (I use this to create an effective variant human)
- Spell Sniper Fix
- Invocations Expanded
- SCAG Cantrips (booming blade et al)
- PHB Dragonborn Breath Weapon Fix
- Feats Extra
- Full Release Mod Fixer
- Fix Bad DM (changes jump/shove into full actions -- makes terrain and fields like grease et al far more relevant)
- PHB Ability Score Revert
- Approval Tweaks (Absolutely necessary to not have the whole thing turn into some weird polyamorous polycule after like half an hour)
- Realistc Carry Weight (makes strength matter quite a bit)
- Hide Quest Markers