I think that's more a question for you - what do you mean by "best"?
What is
your appetite for potential downtime and do you have the time to try and find and fix any issues?
What is
your use case for FreeBSD? What are
your production systems, and how much stability do you value? What do you run on them, what performance criteria do you have?
And as SirDice said "you obviously tested ... before pushing it to production" which is going to be true of any release of any operating system.
14.1 is the newest version of FreeBSD, with the most changes, so it's probably a
little bit more exciting to use in production, but at some point the 13.x line will go EOL, so at some point you will need to be on 14.x. What time suits you and your production systems?
13.3 should be more stable (because bigger, newer changes will be in 14.x or 15.x), but it was a bit more exciting than usual with a ZFS bug, quite a clang/LLVM jump, sendmail changes, etc.
FreeBSD 13.x will be supported until 2026, 14.x until 2028:
www.freebsd.org
Personally I prefer conservative, so all my production machines are 13.3, but some of my development machines and backup machines etc. will be 14.1 as I test and evaluate 14.x and see if I have any issues with
my production environment. I probably won't have 14.1 in production this year, but maybe one or two servers in 2025.
I don't think you can go wrong with either 13.3 or 14.1, but only you can determine that. You'll see people having various issues with various upgrades - maybe one of those issues will affect your production systems?