This has been asked many times, did you try a search ?
Anyway hardware should point you to either OpenBSD or FreeBSD. If you have Nvidia, OpenBSD is not an option. Once you know if your hardware is fine, it mainly depends on your needs.
See what applications are needed and check on the status of the 2 OSs, Outside of security, I think OpenBSD is easier to install and maintain, FreeBSD may work better on your hardware.