The best replacement for qemu is virtualbox.

The best alternatives to qemu are rated as following:
★★★★★  virtualbox
★★★  kvm
★★★  xen
★★★  bochs
★  qemu-kvm
★  dosbox
★  qemu-system
★  simics
★  openvz
★  lxc
  libvirt
  kvm hypervisor
  virtual pc
  kqemu
  virtual box
  colinux
  vbox
  pearpc

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

Other search terms related to qemu and their ratings are:
★★★★★ kvm
★★★ xen
★★ spice
★★ hardware virtualization
You have in mind a companion for qemu and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of qemu in all years. Click on graph for more.
qemu
virtualbox
kvm