I prefer Fire Fox on many levels. Firstly IE sucks bug time LOL!
No, really, from an SEO point of view I prefer firefox due to the add ons that I can have that are not part of Fire Fox
It looks better and renders websites in a better format, I think I am a Microsoft hater which is probably more the reason than anything else, IE6 for example is a pile of crap and should have been removed by now, surely the only people left using IE6 are on pirate copies of Windows, so, who cares, remove IE6 and make them have the up to date version which would save programmers a ton of work, as per usual IE renders websites in a worse manner than Fire Fox - I wish all the browsers would just get together to save us programmers from having to programme for each individual browser like Safar, Fire Fox, IE etc
So, Fire Fox rules vs IE but this is just my personal opinion, I have now removed anything Microsoft from my machine and now use OpenOffice as this is free