My single-box Vagrant settings, VMware Fusion Edition.

Vagrantfile

# -*- mode: ruby -*-
# vi: set ft=ruby :

Vagrant.configure("2") do |config|
  config.vm.box = "precise64"
  config.vm.network :private_network, ip: "192.168.33.2"
  config.vm.synced_folder ".", "/Projects", id: "vagrant-root"

  config.vm.provider(:vmware_fusion) do |v|
    v.vmx["memsize"] = "2048"
  end
end