Firefox on linux. I hear claims that Chrome/Chromium is faster. I don't find that. Firefox has a LOT of useful add-ons. I also find secuity on Firefox more 'granular' though that may be just my feeling. I may find myself installing Chrome because newer versions of Flash are not available for linux. Hasn't been an issue so far though, flash 11.x does what I need it to do. I'm pretty sure Google knows enough about me, they don't need to know more.