Of the three, I'd prefer Opera. However, because of browser driven development, I use IE7 alot. The current Hierarchy of browser usage for me is IE7, then Opera, then Browzar (standalone IE alternative that automatically clears its own caches when closed), and then Firefox.
to make IE7 more like Opera, I also have a FREE add on for IE7 called
IE7Pro. Among other things such as forcing single instances, extra ad blocking, flash blocking (really really nifty) dictionary and spell checker, address bar macroing (like putting in "ts" for
www.techspot.com/vb/ ), and custom user scripts, it also includes customizable mouse gesturing (what a fun feature in Opera. =), now it can be used in IE! ). Best of all, it makes IE just as feature rich as Opera, but its still more bloated and slower though. =p
FF works for what its worth, and is really nice in regards to its impressive library of extensions.
Relying on a program to be secure and to protect you is foolish, as I believe it is more up to the user to be wary of his or her surfing habits, and to practice safe browsing of the Internet and not open emails that you do not know who they are from (or blatantly spam).
As we say in the office, the weakest point in a security system is not necessarily the programs used within it, but the people who use the programs.
~madboyv1