which is the best technology to built database driven sites?

Out of cold fusion, BAL, PHP which is the best??

To have database driven site is not depending on programming language or used technology, you should choose choose the suitable approach by other aspects than the site being database driven site.

From a technology stack point of view you need to look at three things. I am only advising Linux based stack.

Scripting
For scripting technologies, you have Php, Ruby on Rails (ROR) and Python that tend to be most used. Cold fusion will also work, though unfortunately it seems to have lost interest in the developer community. I am not sure what you mean by BAL. Any of these will get the job done. The choice should finally be based on what you are (or your developer is) comfortable with.

Database
More often than not it is the database that becomes the choke point for very large data oriented websites. You can choice between MySql, PgSql and SqlLite. Most developers prefer MySql since they have experience with it and it gets the job done in most of the cases.

Web Server
If you have a lot of traffic to your website, then the web server choice makes a big difference. Nginx tends to be a lot better than Apache (out of the box). More and more websites are moving over the Nginx.

A typical technology stack would be LEMP (Linux Nginx MySql Php) or LAMP (Linux Apache MySql Php). Most web hosts generally have default setup for LAMP.

Your question is very generic. You should try to specify your question.

Out of the choices you offered and the few information you provided, I'd say PHP.