Ubuntu Server edition has JeOS option ( http://en.wikipedia.org/wiki/Ubuntu_JeOS ) which is a minimal install optimized for virtualized environments.
Yes, one could add the gui afterwards, but something minimally configured already would be a timesaver...
If the original poster is looking for a VM to distribute an application, JeOS is a reasonable place to start.
On the other hand if the original poster wants to run a VM for every application he will (likely) want to look for a VM platform that dedups memory, a la ESX (though that's a bare metal server hypervisor)
If the original poster just wants a secure enivornment to run apps, something like VMware ACE may work better which allows you to lock down/filter access to USB storage, network, etc.
Disclaimer: Former VMware employee.