If you can afford the 760, it is the best option. The 760 is very similar to the 660 Ti but a little better in performance. Also it's technically next gen, so it will get the most love as far as drivers go. The 760 will more than suit you needs for those titles 60 + in Wow and MC (BF3 might only get 45-60 FPS on max) That i3 souldn't bottleneck the card, so don't worry about that.
Yeah, and I reccomend Geforce Experience for Nvidia gaming. It suggests the best gaming settings for your setup.