It's not hard to find lists with dozens of great plugins for Firefox but I can't remember the last time I saw such an article for Internet Explorer. Anyway, ExtremeTech just compiled a list of ten fantastic IE add-ons:
The problem with IE add-ons is that most of them cost money. Finding decent, free ones is hard enough; even searching for free IE add-ons turns up scores of IE toolbars and little else. Toolbars! It seems like virtually every company with a product of some sort has an IE toolbar, evidently trying to capture the success of the ubiquitous Google Toolbar. Do we really need toolbars for casual game publishers, or for jazz radio?
We spent hours digging through the toolbars and other freebies to find ten totally free IE add-ons that don't suck. We split them into two categories: Useful Stuff and Fun Stuff. Each entry links to the Windows Marketplace page where you can find more information and a download link for each add-on.