I have mixed experience with the site sharekhan dot com, but mostly positive. On the positive side, their charges are reasonable and the customer responses are quick and informative. On the negative side, their server downtime sometimes is longer than expected. However, in the recent time, this has improved.

On a comparative note with similar kinds of websites, ICICI direct requires an account with ICICI bank, and this is restrictive. The other site 5paisa I have not tried at all, and therefore cannot or will not comment. indiabulls is also good in terms of interface, but their customer service is poor.

You have to decide which is most important aspect for you, and then decide your trading partner. In other words, the long term investor and the short term investor and the broker - all have different priorities, and therefore, will have different expectations from a trading website.
That is all I have to offer.