If an ordinary shared hosting plan is too little for your websites, you can take a look at highend shared hosting plans. These are like regular shared hosting plans, except they are bigger, and there is a strictly limited number of accounts on one server so you can use more cpu without slowing down the server.

Disc quotas on these accounts are often measured in gigabytes, and normal quotas range from 500 mb to 20 gb. So one of these accounts can be ideal for very large websites. And data transfer quotas are of course higher than normal.

Server resources

More importantly, a highend shared hosting account offers more cpu resources, because there are fewer accounts on the server. Some scripts can be very cpu intensive, forums are a good example. Many web hosts have limitations on use of forum scripts because of this. If you are having problems with cpu resources, an upgrade to a highend shared hosting account can solve the problem. You don't get the full power of a dedicated server, but it will provide cpu resources for more demanding sites than a regular shared hosting account can.

Another point worth mentioning is security. Because you are still on a shared server, there are security risks like on any other shared server. But the risks will be more limited, simply because there are fewer users with access to the server.

And because a highend shared hosting account is just like a regular shared hosting account except for the size, it does not require any more computer skills. This is the main advantage of highend shared hosting over dedicated/virtual private servers.

Pricing

You might find web hosting plans including something like 1gb of disk space and 50gb data transfer for $10-$20/month. These are not highend shared hosting plans as discussed here. Web hosts offering these plans are overselling their servers, and can not offer the same level of performace as a real highend shared hosting plan. Highend shared hosting plans are priced at around $50/month and upwards.