The best replacement for raspberry pi is arduino.

The best alternatives to raspberry pi are rated as following:
★★★★★  arduino
★★★★  beaglebone
★★★  ouya
★★★  arduino uno
★★★  chromecast
★★  galileo
★  cubieboard
★  htpc
★  cubox
★  udoo
★  pogoplug
★  android mini pc
★  apple tv 2
★  g box midnight
★  android stick
★  odroid
★  beaglebone black
★  nuc
  pcduino
  wd tv live
  intel atom
  cubietruck
  via
  android tv

Your alternative for raspberry pi is not listed? Suggest!
Speaking about raspberry pi, one probably shouldn't forget about xbmc.

Other search terms related to raspberry pi and their ratings are:
★★★★★ xbmc
★★★★★ arduino
★★★★ wifi
★★★ touch screen
★★★ wifi dongle
★★ remote control
★ keyboard and mouse
arduino projects
You have in mind a companion for raspberry pi and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of raspberry pi in all years. Click on graph for more.
raspberry pi
arduino
beaglebone