I like Chrome personally. Find it runs a bit better than firefox on my laptop, but also has that extension ability.
I like Chrome because it's easy to sync my bookmarks between my desktop, laptop and phone I know I could probably do that on Firefox too but I think it'd require an add-on. Also I reckon it looks nicer. Still have firefox though and do use it occasionally.
I use Safari and I find it fine. But I don't know anyone who thinks that it's the best. It's basically Apples Internet Explorer.
Opera was my fav, and I still use it every now and then, but any time I updated it, the devs tried to slick up the design, and it just became worse and worse. Less doesn't mean better. Using Chrome for most things now though, Opera isn't supported by some sites outside of third world eastern European countries or whatever. Chrome doesn't leak memory as much as Firefox does either.