Opera is great! I actually use two browsers regularly: Opera and Firefox.
In Opera I keep open sites that I visit regularly, like my own site, some forums, auctions and so on. I typically have around 10 pages open in Opera. Also I use Opera for reading newsgroups and as an feed aggregator, it actually has the best feed aggregator there is! I like to have the important pages always open and get them all opened quickly when I turn on the computer. Opera has this fantastic feature of saving and reloading open tabs on program start.
Firefox has some features that I like better than Opera. First of all the NoScript plugin. When I browse for something new, do searches or move in sites that I'm not regular, I prefer Firefox and blocking scripts and cookies. I am slightly paranoid about security and privacy

Also it's a fact that more sites work better with Firefox than Opera. I think the best known examle would be YouTube with which my Opera has problems with full screen video.
Oh and even better than the desktop Opera is the Opera for smart phones and PDAs. I've got a series 60 cell phone and I bought Opera browser to it. And man it rocks! It really does miracles for rendering normal websites to the small screen and the designers at Opera software have done incredible job with the usability. The cell phone Opera has saved me from a lot of trouble.
Comment/Reply (w/o sign-up)