The best replacement for ec2 is linode.

The best alternatives to ec2 are rated as following:
★★★★★  linode
★★★★★  s3
★★★★★  azure
★★★★  rackspace
★★★  vpc
★★★  google app engine
★★★  aws
★★  rds
★★  heroku
★★  vps
★★  google compute engine
★  elastic beanstalk
★  digitalocean
★  emr
★  gce
★  dedicated server
★  gogrid
★  pinstripe
  ec1
  softlayer
  app engine
  slicehost
  azure pricing
  digital ocean
  beanstalk

Your alternative for ec2 is not listed? Suggest!
Speaking about ec2, one probably shouldn't forget about ebs.

Other search terms related to ec2 and their ratings are:
★★★★★ ebs
★★ s3
You have in mind a companion for ec2 and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of ec2 in all years. Click on graph for more.
ec2
linode
s3