I still use IE6 and I think it’s the best browser out there a part from IE5 of course.
FF has some major memory issues when using multiple tabs and the modx manager... I have seen it hitting as high as 700mb of physical ram usage with just 8 tabs open. It does feel rather clunky but it does have the best addons and does represent your design how it should be seen.
Safari is not bad... it does have some CSS issues that I saw but overall it’s ok. Similar to IE it does require some CSS hacks.
IE7 is better than 6 but still has CSS issues... it seems to be 3-5px out with some alignments etc so hopefully IE8 will sort that out..................................... time will tell!
Chrome is really nice, it’s fast and lightweight however it doesn’t support RSS that I see? Well there’s no template or something as it just displays the raw text feed. Also there are some elements that are similar to IE6 and require CSS hacks.
Opera is pretty good, I found it similar to FF representation of sites.
I will use any browser that work, doesn’t crash and displays a true representation of a site design.
Overall I use FF the most due to firebug etc but the memory use and the over all clunky feeling does stop it from being a true great.