There are three browsers I used the most: Chrome, Safari, Mozilla. I rarely used IE and Opera since 2002 so I wont comment on those two. Here is my Pros and Cons about those browsers.
Notes: Test ran on OS X, no plug-in to keep it fair.
Pros: fast, effective, I can easily find what I want due to the settings is very similar to OS X, tabs easy to manage, UI is easier to manage
Cons: cant redirect to google at address field(has it own field for google), terrible at flash
Pros: quite fast, google at address field make things easier to google, tabs easier to manage, better at flash than Safari, Save Password and Translate Page feature sometimes can be very helpful, recently closed page is great.
Cons: opening multiple page sometimes make it very slow and crash the browser, non typical OS X menu sometimes annoying, History is confusing
Pros: fast, address bar figure out on its own what you want to find.
Const: address bar figure out on its own sometimes very annoying, the result is unpredictable, google has its own field
There you go. Most of the times I use Chrome. But sometimes a few page with missing plugin are easier to install and open with Safari.