don’t give more to someone then they give to you
I tend to disagree on that one. Random acts of kindness/selflessness to people, even complete strangers, can bring bonus satisfaction to your life (and sometimes will be paid back). Make it a habit to give to people, when you have the chance, especially if it is low effort.
If you have people around you that just constantly leech off of you, then I agree: don’t let yourself be sucked dry.
Earthlings (2005) was life-changing for me, opening my eyes to veganism. A more recent version is Dominion (2018).
But these deal with a gruesome topic. Planet Earth (2006) is more suitable for “favorite”. It blew me away, because I’ve never seen wildlife footage like this before.