The best replacement for three is 3.

The best alternatives to three are rated as following:
★★★★★  3
★★★  two button suit
★★  four leaf clover
★★  o2
★★  tree
★★  four children
★★  vodafone
★  two kids
★  ee
★  four musketeers
★  giffgaff
★  two children
★  four kids
★  four blade prop
★  redux
★  three
★  prius five
★  prius v five
  o2 coverage
  two blade props
  prius four
  alpha one
  two button suits
  bravo one

Your alternative for three is not listed? Suggest!
Speaking about three, one probably shouldn't forget about you feels.

Other search terms related to three and their ratings are:

★★★★★ you feels
★★★ 4g
You have in mind a companion for three and it is not yet here? Propose!

Google Trends

Scale is based on the average worldwide traffic of three in all years. Click on graph for more.
two button suit