The default apps work fine for me... I use "notes" and sync it with my google account using the default mail app. The only 3rd party app I use a lot is "WhatsApp" - and that's just to text some friends around the globe.

I then have a few games and some useful server monitoring apps... as well as some comics. 3-4 pages of 3rd party apps maybe? But none of them replace the defaults for me...