I'm pretty fond of Safari, but if it's not used on Mac, it doesn't seem to give me the same feel, sadly. If it weren't for that, it would have been the default for each and every one of my computer.
Aside from above, I love Chrome. Have installed it about two years ago, and have never looked back since then. It's optimized, simple, elegant, saves all your browsing data in-cloud (log into your Google account from any computer running Chrome browser, and you're all set), and it doesn't consume much resources, or so I've heard. Before, I was on Firefox, but sadly, something about it just didn't click for me.
On my phones, I run Opera Mini. Just like Chrome, it's fast, simplistic, and so forth. Though, one advantage it has is that it's made in such a way that regardless how much you browse, it wouldn't devour much data at all. This helps, especially when I've got some data-cap.