The best replacement for iphone 3g is 3gs.

The best alternatives to iphone 3g are rated as following:
★★★★★  3gs
★★★★  iphone 4
★★★  iphone 3gs
★★★  nokia n97
★★  4
★  iphone 4g
★  2g
★  blackberry storm
★  blackberry
★  blackberry bold
★  ipod touch 4g
★  iphone 2g
★  instinct
  ipod touch 2g
  ipod touch
  iphone
  captivate
  3g s
  android
  blackberry curve
  omnia
  g1
  samsung omnia

Your alternative for iphone 3g is not listed? Suggest!
Speaking about iphone 3g, one probably shouldn't forget about ios 5.

Other search terms related to iphone 3g and their ratings are:
★★★★★ ios 5
★★★ ios 4.3
★★★ tmobile
★★★ 4.2
★★★ t-mobile
★★★ ios 4.2
★★★ samsung omnia sgh-i900
★★★ nokia 5800 xpressmusic
★ 4.3
★ ios 4
★ facetime
★ simple mobile
★ no wifi
4.2 update
You have in mind a companion for iphone 3g and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of iphone 3g in all years. Click on graph for more.
iphone 3g
3gs
iphone 4