Depends on what you mean by success. If by success you mean money, fame, number of people who like you and dream about you and think about you, for ages to come, easier life everywhere you go, then looks count way more than intelligence... I guess looks are generally way more helpful for success, just that easy. Intelligence can get you all those things too, but not as strongly, I'm sure.
If you're a girl "The extremely beautiful with average intelligent " as no matter what you achieve your worth as a woman will be based on your youth/beauty. As well as while one can usually increase their knowledge while outside of surgery one cannot increase their beauty.
If you're a guy either one.
The extremely beautiful can be more likely to be more successful.
Just look at Kim Kardashian for example.
She is not even averagely intelligent and never even went to college to heighten her education. Yet has made millions because society thinks she is beautiful. She's more successful than some of the highly intelligent, wonderful average and below average looking people I've met.
I knew a beautiful girl who got a lot of things handed to her just for being pretty. She's had someone give her free sunglasses in a store, she has gotten jobs where her manager said "I hired you because you're pretty and I thought you'd attract business", and overall people are more open and friendly to her all because she's attractive.
I've seen not so attractive, average or ugly girls who are so intelligent and have a lot of personality get outshined by a pretty girl who doesn't even have all that much to bring to the table where it counts.