I don't understand these kinds of threads. They pop up so often, and it's the same answer every time: play whoever you want. We don't really care who you play, and I don't say that to be rude, just that it doesn't effect us in any way. This is something that is completely up to you. Like your mother probably once said, "If your friends jumped off a bridge, would you too?"
Fox and Falco are both great characters, and either one is a great choice. But whichever one you ultimately decide on should be something you decide on your own after experimenting and practicing them both. Practice every character in the game, in fact, you may never know what character clicks with you. I never expected to play a character like Bowser, one of the worst in the game, but after trying him I found him to be my favorite character of the cast. Just mess around with everyone until you come to a final decision. It took me over a year to settle down on Fox.