I would bet on NoScript's filters being much better than those in Internet Explorer or Chrome, because Giorgio has a much faster release cycle and doesn't have to be as conservative as browser vendors do.
However, it's not just XSS you have to worry about. CSRF is not quite as dangerous, but can still do a lot of damage, and is much harder to prevent. Internet Explorer, Chrome, and Safari will do nothing to save you there.
They don't generally protect you from clickjacking, either (X-Frame-Options is only a partial defence, and only works at all if the victim site supports it).
Running OSX will usually protect you from drive-by-downloading a keylogger or becoming part of a botnet. But the more your data and activities move online, the more damage an attacker can do without needing to leave your browser.
However, it's not just XSS you have to worry about. CSRF is not quite as dangerous, but can still do a lot of damage, and is much harder to prevent. Internet Explorer, Chrome, and Safari will do nothing to save you there.
They don't generally protect you from clickjacking, either (X-Frame-Options is only a partial defence, and only works at all if the victim site supports it).
Running OSX will usually protect you from drive-by-downloading a keylogger or becoming part of a botnet. But the more your data and activities move online, the more damage an attacker can do without needing to leave your browser.