FireFox, because for one thing it has the coolest name/logo.
internet explorer? Isn't that just what it does? How original... And their logo is just a lower case "e" with something going around it, why? It must be because it starts with an "e" and the internet goes around the world. How fantastic and imaginative...>.>
Opera? I just imagine a fat lady singing in a viking costume, not a pretty sight, so I don't like it just for that mental image. It looks like they just took a random word and made it their name... kind of weird. And their logo is just a freaking "O" What the hell? they couldn't even be bothered to think of anything to represent their browser? Lazy bastards. Side note: Isn't an "O" already the symbol for about 200 other things?
Safari? I just imagine that "tally-ho" hunter guy from pink panther(the show) every time I here that word. I get what they were trying to say, "You can tranquillize elephants on our browser" Okay, not that, but that's all can think of, the name is too distracting and doesn't have enough to do with the project. And now their logo, a compass... What? I guess it's better than a letter... possibly... more strange than anything else, why a compass, you used to use them in safaris, I think? At the end of the day it's just really vague and loosely connected, much like the name of the browser.
But "FireFox" can you imagine anything that would make you go "WHAT FUCK WAS THAT?!" and then "THAT WAS THE COOLEST THING I HAVE EVER SEEN IN MY LIFE!" than a giant fox on fire running around the planet. While in doesn't have anything to do with the internet, the logo does, and they are both awesome, and that is how I choose my browsers, on how cool they are.
As well as it is the best browser(that I have tried, which is really just an old version of IE and FireFox).