I keep all the alternatives installed and updated on my dev PC, so I can check my sites work with them all, but I use IE8 as my standard browser, because I'm really not interested in features other than the address-bar, don't much care about rendering speed of the sites I visit, and can't be bothered trying to learn another program.

 

However, that doesn't mean I think IE8 is a good browser, it's just not bad enough to make me want to switch.