which upgrade should i get?

[Talal Siksek]

My pc
corsair 750w psu
Mars blue case
Asus z87-k
8gb Corsair ddr3 ram 1866mhz
i5 4670k 3.8ghz
intel heat sink
GTX660
1tb western digital caviar black

those are my parts i'm thinking of upgrading. Either another graphics card and running SLI, a new case and a closed loop liquid cooler plus some overclocking or a big air cooling system and an ssd. which is the most benificial for an all-round smoother windows experience and gaming experience?

 

[RealBeast]

For all around the best would be an SSD. For gaming another graphic card in SLI would be the most helpful.

 

[hizodge]

Your motherboard regrettably has no SLI support so I would get a new case, some cooling and get a decent overclock on that CPU. What kind of a budget are you working with here?