YouTube Decade - Watch the most viewed videos posted exactly 10 years ago
Hover Zoom - Enlarge thumbnails on mouse over.
CDNPerf - CDN performance and uptime statistics
Imagus - The extension is intended to complement image features that (I think) is missing from Opera by...
mlytics - Boost websites and apps faster and safer
Image Max URL - Help find larger or original versions of images, including a customizable image popup feature