After not touching legos for like 10 years I got myself the 42082 set a few years ago and I had a really good time with it. But now my lego fever has awoken once more and I was wondering what set would you recommend if I'm also planning on getting into MOCs and GBCs 

3rd set.

Considering you want functions, I recommend the 42139 and 42128. Also the upcoming 42157 looks very promising.

Also, the Airbus helicopter 42145 has been universally praised for its realistic main rotor functionality and functions in general.

 

If you want to get into MOCing, then you could consider picking a set that has colors you already have, so you can expand your collection in a particular color so you can build more models in that color faster.

All of the sets mentioned previously are great and highly recommended.

I would also recommend looking for second hand sets and maybe also mixed piles of Lego, especially if you're into GBC - with those you'll probably want to have a decent collection of System parts too. Buying second hand will get you more parts for less expense, if the expansion of your parts collection is what you're firstly looking for. If you want the experience of opening and building a set, then the only practical option is of course buying new sets.