IE8 in work, but have used firefox since v1.6.
I liked the positioning of the tabs in Chrome, but the availablity of AdBlock Plus pulled me back to Firefox. Might give Chrome ago now that there are a couple of ad blocking projects: https://chrome.google.com/extensions/detail/gighmmpiobklfepjocnamgkkbiglidom
https://chrome.google.com/webstore/detail/cfhdojbkjhnklbpkdaibdccddilifddb
I liked the positioning of the tabs in Chrome, but the availablity of AdBlock Plus pulled me back to Firefox. Might give Chrome ago now that there are a couple of ad blocking projects: https://chrome.google.com/extensions/detail/gighmmpiobklfepjocnamgkkbiglidom
https://chrome.google.com/webstore/detail/cfhdojbkjhnklbpkdaibdccddilifddb