The best replacement for usb 2.0 is firewire.

The best alternatives to usb 2.0 are rated as following:
★★★★★  firewire
★★★★  3.0
★★★★  firewire 800
★★★  firewire 400
★★  esata
★★  1.0
★★  1.1
★★  usb 3.0
★  usb 1.1
★  ethernet
★  gigabit ethernet
★  usb 1.0
★  firewire 400 faster
★  firewire speed
  firewire 800 faster
  thunderbolt
  ethernet faster
  usb
  usb 3.0 speed
  gigabit
  1394
  esata speed
  firewire faster
  3.0 cable
  gigabit ethernet faster
  ieee 1394
  3.0 symbol

Your alternative for usb 2.0 is not listed? Suggest!
Speaking about usb 2.0, one probably shouldn't forget about 1.1.

Other search terms related to usb 2.0 and their ratings are:
★★★★★ 1.1
★★★★★ 3.0
★★★★ usb 1.1
★★★ usb 3.0
★★ 3.0 port
You have in mind a companion for usb 2.0 and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of usb 2.0 in all years. Click on graph for more.
usb 2.0
firewire
3.0