The best replacement for atmega is pic.

The best alternatives to atmega are rated as following:
★★★★★  pic
★★★★  attiny
★★★★  xmega
★★★★  msp430
★★★  8051
★★  at90
★★  avr
★★  stm32
★  atxmega
★  atmega
★  cortex m0
  magic card

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

Other search terms related to atmega and their ratings are:
★★★★★ usb interface
★ enc28j60
You have in mind a companion for atmega and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of atmega in all years. Click on graph for more.
atmega
pic
attiny