Opera since....damn, way, way back. So far back I paid $35 to eliminate ads and get one on one customer support!
So many features, like saving pages in one simple MHTML file. I think only IE has this. My search bar has Find in Page, Ebay, Amazon, and Wikipedia. Always right there.
I'm talking about Opera 12 point something. A few months ago they rolled out v.15, now 16. Turns out it was a complete rewrite using the Chrome engine! NOT Opera. No features I love.
Firefox is my secondary, a lot of nice plug ins. But still not having what I love in Opera, like the save pages to MHTML....unless I've missed that. Every try to save a page in Chrome? Ha!