NoScript is the reason I won't consider switching to a browser other than Firefox. It's white-list based script blocking made convenient. It blocks all scripts, including javascript, java, and flash. It is easy to allow on a per-domain basis. It also protects against XSS. I feel vulnerable if I'm not using it.
It also drastically speeds up page load times, and cuts out almost all ads. It also blocks scripts from tracking sites, including most analytics companies (except those that use images instead of scripts for tracking, which are very few anymore). AdBlockPlus takes care of the rest.
Here is the description from the NoScript page (
link):
The best security you can get in a web browser!
Allow active content to run only from sites you trust, and protect yourself against XSS and Clickjacking attacks.
http://noscript.net said:
NoScript's unique whitelist based pre-emptive script blocking approach prevents exploitation of security vulnerabilities (known and even not known yet!) with no loss of functionality...
You can enable JavaScript, Java and plugin execution for sites you trust with a simple left-click on the NoScript status bar icon