Well every girl will be attracted to different things but me a guy needs to have good hygiene and fresh smelling breath, a nice fragrance (even if he doesn't wear perfume/cologne he should smell fresh and clean), good dress sense (different girls like different styles so your individual style might not appeal to everyone), a cool hairstyle (I like haircuts that are a little unique and different like bleached hair or spiky hair or long hair), an air of confidence about him. He needs to look like he keeps in shape and cares for his appearance too but not in an overly vain way.
Personality-wise I like a man with a good sense of humor, sweet, caring, strong, intelligent, and honest. I think it's important that a man should just be himself when he talks to you because if he's being fake then eventually that will be totally apparent later on in the friendship/relationship. I hate selfish, egotistical, and arrogant men so those things would dampen my attraction to any guy.
Out of everything the most important things for me are good hygiene, keeping in good shape, sense of humor, and intelligent but some girls will put less emphasis on those things and more emphasis on others (although I think a desire for a guy with good hygiene is pretty universal) so make sure that you're freshly showered and minty-fresh and then just be yourself with the rest of it.