This really depends.

If the site is newer or is currently on a shared environment, the next natural step is to a VPS. If the site needs its own dedicated environment, it's always possible to upgrade from VPS to a dedicated server once the traffic warrants it.

With a dedicated server you will have full use of the entire server. A VPS is still a shared solution (albeit one with much more flexibility) and resources are shared with other VPS's hosted on the server.


Regards,
Support Team
Hostgator India