My personal opinion.
If it is not broken, don't fix it.
If you were to upgrade, between AMD and INTEL, the choice would be based off the applications you are using it for.
I would pick whichever is best for your MOBO socket, has the least power consumption for performance. One that fits your cooler aswell.
The CPU's all perform around the same levels with slight variances, so Its not really which one is the best for me, its which one works the best for my current usage and applications.
For gaming like you said, I would use an AMD CPU, but this is my opinion. I have had better performance when it comes to intensive gaming with AMD vs INTEL.