At this time of year we usually wish our friends and family all the best for the New Year. We also use this expression at the end of emails as it is a friendly and informal way of saying goodbye.
Here are a few other expressions with best:
had best = ought to/should
You’d best get up earlier tomorrow so that you’re not late for the interview.
Be for the best = be desirable in the end, although at first it may not seem so
I was very upset when my parents got divorced, but now I understand that it was for the best.
The best part of = most of
I spent the best part of the weekend cleaning the house.
Make the best of = to use resources as well as possible
The students are encouraged to make the best of what they have learnt during the course in the team projects.
Get the best of = to gain advantage over
When I saw his phone, my curiosity got the best of me and I looked at his messages.