The best replacement for gu10 is mr16.

The best alternatives to gu10 are rated as following:
★★★★★  mr16
★★★★★  par20
★★★★  gu5.3
★★★  gu24
★★★  gu10+c
★★★  mr16 difference
★★  e27
★★  mr16 led
★★  gx10
★★  gu20
★  mr11
★  low voltage
★  par16
★  gz10
★  br30
★  par30
★  gu4
  mr16 halogen
  gu10 c
  mr16 bulb

Your alternative for gu10 is not listed? Suggest!
Speaking about gu10, one probably shouldn't forget about mr16.

Other search terms related to gu10 and their ratings are:
★★★★★ mr16
You have in mind a companion for gu10 and it is not yet here? Propose!



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gu10
mr16
par20