The best replacement for unlocked phones is locked phones.

The best alternatives to unlocked phones are rated as following:
★★★★★  locked phones
★★★★  no contract phones
★★★★  locked

Your alternative for unlocked phones is not listed? Suggest!
Speaking about unlocked phones, one probably shouldn't forget about metro pcs.

Other search terms related to unlocked phones and their ratings are:

★★★★★ metro pcs
★★★★★ straight talk
★★★★★ boost mobile
data plans
You have in mind a companion for unlocked phones and it is not yet here? Propose!

Google Trends

Scale is based on the average worldwide traffic of unlocked phones in all years. Click on graph for more.
unlocked phones
locked phones
no contract phones