Some of my favorite apps on F-Droid and the apps they help replace:
Floris Keyboard - Gboard
Bromite - Chrome
OsmAnd+ - Google Maps
Editor - Google Keep
My Expenses - Mint
NewPipe - YouTube
LibreSpeed - Ookla Speed Test
Currencies - xCurrency
Diary - DayOne
Password Store - 1Password
Aegis - Authy
WireGuard - All VPNs
Book Reader - Acrobat
Pluvia Weather - Weather