These are what I use:
- Firefox -
Adblock Plusbetter facebook! - various options to hide annoying facebook "features"
http://noscript.net/ - block javascript, java and various other plugins on page. you need to enable the script you want manually. This will break most pages by default, so if something broken when you installed this, checks what it's blocked.
refcontrol - to get around the imageshack domain not registered msg
WebMail NotifierBetterPrivacy - BetterPrivacy is a safeguard which protects from usually not deletable LSO's on Google, YouTube, Ebay...
- Google Chrome -
Adblock PlusAll Mangas Reader - for reading mangas, of course
Disconnect - Stop third parties and search engines from tracking the webpages you go to and searches you do.
Ghostery - Protect your privacy. See who's tracking your web browsing with Ghostery
Open _new & _blank in new background tab - Force links that have _new or _blank in their target to open in a new background tab.
reddit enhancement suite - urmm, it's for reddit. go figure it out
Wikipedia stare fix - Hides Jimmy's annoying stare.
p/s: I open fb on firefox, daily websites on google chrome. Yes, I'm a paranoid android :3