The best replacement for thunderbolt is bionic.

The best alternatives to thunderbolt are rated as following:
★★★★★  bionic
★★★★  firewire
★★★★  iphone
★★★★  usb 3.0
★★★  mini displayport
★★★  iphone 4
★★★  evo
★★★  hdmi
★★★  usb
★★★  droid x
★★  droid bionic
★★  thunderbolt 2
★★  usb 3
★★  esata
★★  thunder
★★  atrix
★  discharge
★  firewire 800
★  displayport
★  lightning
★  thunderpunch
★  incredible
★  lightning apple
★  charge
★  inspire
★  imac
★  sata
★  thundershock
★  ethernet
  revolution
  pcie
  mini dvi
  volt switch
  thunderpunch dragonite
  iphone 5
  htc evo
  usb3
  incredible 2
  ethernet speed
  droid charge
  htc rezound
  cinema display
  verizon iphone
  wait for bionic
  usb 2.0
  electro ball
  evo 4g
  warthog
  lightning bolt

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

Other search terms related to thunderbolt and their ratings are:
★★★★★ pc
★★★★ mini displayport
★★★★ imac
★★★ mac pro
★ mac mini
You have in mind a companion for thunderbolt and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of thunderbolt in all years. Click on graph for more.
thunderbolt
bionic
firewire