I have a dedicated server. I read here that VPS is better because it can be booted and restarted quickly. I'm not sure if this applies to my case or not, but my question is:
Is it better to have 1 VPS that's setup to take all full resources of the machine than to install the OS directly on the full resources of the machine without virtualization?
A VPS is great for several reasons. You get sweet isolation if you run multiple on the same system, along with pausing/resuming/migration features...
However, if you're just running a single VPS on a single dedicated server; that VPS won't have access to the full resources of the server simply because you must run two kernels (the system itself, and the virtualized system).
If you have IPMI on the server, aren't planning on using the external server for anything but the single VPS, and aren't planning on using any cool virtualization features, you'd quite probably be better off just throwing whatever your application is on the server directly.