I've tried the AOSP browser, and really just didn't care for it. I have tried Firefox, Opera, and Dolphin as well, and I just keep going back to Chrome.
A friend of mine has an iPhone, so normally he of course uses Safari. I put Chrome on his phone for him, and even though he still likes to hug the big Apple, I can say that Chrome is better in iOS as well.
Just as a side note, it's really funny because I can remember when Firefox first came out for computers, and it was absolutely my go-to browser from that point on. When Chrome first came out, it was Windows-only and it took AGES for them to release it for anything else, and then for a bit it had issues and so I went back to Firefox. But once they had a real full release of Chrome out there, I've found I just can't make myself sit and use anything else, and now on ALL platforms.