What should I upgrade to?

[mrkuddled]

I am currently running an fx 6300 with an Msi gtx 750ti and 16gb ddr3 ram. I also have a 550w power supply and would like to stay in the micro atx tower size. I am looking for a more powerful cpu but not sure what I should get. I would like to play modern Titles at 1080 with max settings. I have a budget of around $350. What should I get?

 

[Dark Lord of Tech]

Save a little more , switch to an intel i5 setup to meet your needs.

 

[geofelt]

With your budget, a $125 I3-6100 should game better.
You will want a lga1151 motherboard and likely 8gb of ddr4 ram.
I think your budget will handle it.
In time, the motherboard will allow you to upgrade to I5 or I7.

 

[mrkuddled]

What would the best motherboard be to go with an i5 4960k and micro atx case?

 

[geofelt]

Define "best"
I think you mean I5-4690K.
Forgetting cost,
When I had one before, I used a Asus Maximus VII Gene.

That said, It would cost no more for a I5-6600K and a asus maximus VIII gene.
With that sort of budget, you might as well go for current tech. It is marginally faster at a similar price.