Update:
Please note the importance of tweaking the RESOLUTION in some games if using a medium gaming card:
http://www.techpowerup.com/reviews/ASUS/GTX_750_Ti_OC/21.html
30FPS is considered the minimum, so in this example 1600x900 would be best. It's actually not that different from 1920x1080 in many games but the frame rate increases.
Please note the importance of tweaking the RESOLUTION in some games if using a medium gaming card:
http://www.techpowerup.com/reviews/ASUS/GTX_750_Ti_OC/21.html
30FPS is considered the minimum, so in this example 1600x900 would be best. It's actually not that different from 1920x1080 in many games but the frame rate increases.