Plz see http://www.namecheap.com/learn/webhosting/index.asp?from=indexpromo I am interested in pro hosting. Does hosting unlimited sub-domains mean that I can host unlimited domain names or unlimited websites?
subdomains are things like sub.yoursite.com so you can have whatever.yoursite.com in as many ways as you want. It does not mean that you can have yoursite.com and yoursite2.com and so on. What you're probably looking for is dedicated hosting or virtual private hosting which will allow you to put multiple domains on your account.
Hostgator names them as addon domains and allows unlimited domains. They give this at 9.95 per month. In fact the hostgator domains are domain1.domain2.com, somewhat like subdomains. Hence my query.