The above image used to crash safari and Mac OS finder but not effect Firefox.
I still feel that Opera is the most secure browser
On a PC I feel strongly that it goes Opera>Firefox>>IE7>>IE6>>>>>Safari(really buggy atm)
On a Mac I feel it goes Opera>Firefox>>>Safari>>IE
Opera is defintiely the most innovative.
On the subject of browsers I really do not like tabbed browsing though it is taking over I always turn it off when I can.
Opera has messed up some web page layouts a few times something that Firefox does less but Opera is definitely the fastest.
Safari and IE both will crash on one line of code(and there are quite a few of them).
var parser = new DOMParser();
parser.async = false;
This one is specific to Safari on intel macs.