Manoj, there is no such thing as a 'best' company. It's about choices and what fits your needs and budget.
In India, there are many providers - Siliconhouse, Bigrock, Net4India, etc... Again, it depends on what you need and how much you're willing to spend. Some providers who provide 'cheap' web hosting are not always good in post-sales support and their infrastructure.
Globally, there are companies like GoDaddy (bad support and lot of limitations though). Rackspace is very good but expensive. Bluehost, Hostgator are pretty decent as well.
One more thing to keep in mind would be the datacenter location - depending on your target demographic. Some Indian companies provide Indian datacenters so if your primary userbase is from India, there will be little less latency as compared to hosting with an US or Singapore Datacenter.
For larger requirements (CDNs), consider Amazon or Rackspace. They're very reliable, but again, CDN's come at a price and are not very cheap for standard shared hosting.