Best Mac OS for Mid-2012 15" Macbook Pro

[sorlag]

Hello,

My 6 year old Macbook Pro is still running the Mountain Lion it came with.
Below are specs:

Mid-2012 15" Macbook Pro
1680 x 1050 Display with NVIDIA GeForce GT 650M
8GB 1600MHz DDR3
750GB HDD

It a lot slower now due to the apps and garbage I have installed over the years.
So I am planning to backup all data, and install fresh OS.

Which OS version would you recommend which will still keep it running well for atleast next 2 years.
I mean the best compatible one with the hardware, without slowing down the machine too much.
I have installers for all the below which I downloaded offline over these years:

- Mountain Lion
- Mavericks
- Yosemite
- El Capitan
- Sierra/High Sierra

Thank you.

 

[ferrarr]

As of today, only El Capitan, Sierra, and High Sierra are still supported by Apple. Mojave comes out 9/24 (Monday).

Personally, I would use the newest. As the newer the OS, seem to operate better.

 

[mrgvd]

El Capitan then High Sierra