Which of these is better for gaming. Some links:
GTX 660- http://www.arvutitark.ee/est/TOOTEKATALOOG/ARVUTIKOMPONENDID-Graafikakaardid-VGA-Nvidia-GeForce-GeForce-600-Series312/GIGA-BYTE-GTX660-OC-2GB-GDDR5-PCIE16-GV-N660OC-2GD-22059
GTX 750 TI- http://www.arvutitark.ee/est/TOOTEKATALOOG/ARVUTIKOMPONENDID-Graafikakaardid-VGA-Nvidia-GeForce-GeForce-700-Series313/MSI-GeForce-GTX-750-Ti-2GB-GDDR5-OC-N750Ti-2GD5-OC-95277
http://www.1a.ee/arvutikomponendid/videokaardid/gigabyte_gf_gtx750_ti_2gb_gddr5_pcie_gvn75twf2oc2gi
GTX 660- http://www.arvutitark.ee/est/TOOTEKATALOOG/ARVUTIKOMPONENDID-Graafikakaardid-VGA-Nvidia-GeForce-GeForce-600-Series312/GIGA-BYTE-GTX660-OC-2GB-GDDR5-PCIE16-GV-N660OC-2GD-22059
GTX 750 TI- http://www.arvutitark.ee/est/TOOTEKATALOOG/ARVUTIKOMPONENDID-Graafikakaardid-VGA-Nvidia-GeForce-GeForce-700-Series313/MSI-GeForce-GTX-750-Ti-2GB-GDDR5-OC-N750Ti-2GD5-OC-95277
http://www.1a.ee/arvutikomponendid/videokaardid/gigabyte_gf_gtx750_ti_2gb_gddr5_pcie_gvn75twf2oc2gi