Opera has been my preferred browser for the last 6 years. It is fast, very secure and intuitive to use. Most new features make their debut in Opera before they are adopted by IE and Firefox: tabs, zoom, RSS reader, password manager, integrated mail client, voice recognition and text-to-speech.
Opera 9.0 was released today. Multiple mini programs, called widgets, are included. Google widget is one of them, it covers almost any Google service you would like to use.
Google widget is not just another toolbar. Give it a try and you will see for yourself. How about a Password Generator, Translator or tinyUrl?
The list of features seems endless.
My only complaint as an Opera user is that due to the low market share of the browser (11 millions or so), some web services (like Google Calendar) do not work well in Opera. For regular browsing though, Opera is simply unsurpassed. Hopefully Google and Yahoo will fix the compatibility issues soon.
Video: Opera browser 12-year history
Opera Voice Feature : Talk to Your Web Browser. Quick Online Tips.