[TekNoir]

In Opera: Alt+P and go to the advanced tab. Select Content and uncheck all options. This makes Opera act like NoScript; not allowing any sort of script or addon to run on the page unless whitelisted. To selectively enable options for a particular domain, right-click on the page and select Edit Site Preferences. This has been around for quite some time in Opera -- which has been on the bleeding edge of web-browser technology since they began -- and it functions better than NoScript in my opinion, especially when combined with content blocking.

You use content blocking to block ads (or anything else you tire of seeing). Right-click on a page and select Block Content near the bottom. The browser then displays instructions near the top. You can find extensive premade block-lists on the internet if you so desire.

Opera also supports user-javascript (think Greasemonkey) if you are into that sort of thing. It is certainly not necessary and goes above and beyond what the NoScript or AdBlock addons do; in its ability alter the content and layout of the page itself.

For what it is worth, Chrome was the only browser not hacked during the first day (or for the entirety of the event for that matter) in the recent Pwn2Own hacking event, due to its built-in sandbox that isolates the browser from the OS. I don't think Opera was in the mix due to low market share, but that should make it less targeted and therefore more safe (to an extent).

Also, the next release of Firefox is supposed to have a "fix" for situation with the Microsoft .NET Framework Assistant addon. It may have already been released by now. *shrug* I don't use Firefox on any of my systems.