I picked Opera mobile (not mini) because
- a reviewer (can't remember which website) stated other browsers are just "skins" on top of the stock browser, so you are actually only comparing stock vs firefox vs opera.
-firefox currently does not support flash, still a very good browser.
- dolphin was good, i liked it...as well as skyfire, i believe dolphin had gestures that was nice. can't remember for sure. one of these browsers had the annoying bar at the bottom that links to social network and such. not my cup of tea.
- opera mini is a bit quicker due to it routing data to opera server first, then it shaves down to only what you need therefore saving you from receiving more data than you really need. BUT it doesn't support flash.
- opera mobile supports flash, does the full browsing without the feature that mini has, yet it's turbo mode offers similar experience.
with opera mobile having what im looking for and does more than 4 tabs at once unlike stock browser, i picked opera mobile.
bottom line i vote opera mobile...for now.
edit: here's the link to the review i mentioned.