The best replacement for gtx 660 is 7870.

The best alternatives to gtx 660 are rated as following:
★★★★★  7870
★★★  7850
★★★  750 ti
★★★  gtx 750
★★★  r9 270x
★★★  660 ti
★★  gtx 660 ti
★★  hd 7870
★★  gtx 760
★★  r9 270
★  hd 7850
★  r7 260x
★  650
★  gtx 650 ti
★  650 ti
★  gtx 750 ti
★  7770
★  650 ti boost
★  560
  gtx 570
  gtx 580
  270x
  radeon 7850
  gtx 480
  560 ti
  gtx 650 ti boost

Your alternative for gtx 660 is not listed? Suggest!
Speaking about gtx 660, one probably shouldn't forget about i5 3570k.

Other search terms related to gtx 660 and their ratings are:
★★★★★ i5 3570k
★★★★★ i5 4570
★★★★ fx 6300
★★★ i3
★★★ i5
★★ i3 4130
★★ core 2 duo
★ i3 3220
★ q6600
You have in mind a companion for gtx 660 and it is not yet here? Propose!



Google Trends

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gtx 660
7870
7850