I, honestly, think this is a bit of a paradox. Someone with perfect social skills cannot be completely retarded or have no talent... part of being social is having something to contribute to the social situation. Someone who is stupid and has no talents can't really contribute, and would not really be considered a valid sociable individual.
That said, assuming they are very shallow in such departments - I would say, of the listed options, they are ranked as second in the most likely to be successful.
Ranked third.
There is, however, the exception if he/she is very motivated and industrious. In that instance, he/she could literally bootstrap his/her way to some form of success. That takes exceptional fortitude and exceptional genius. Social skills and attractiveness are important in developing bonds that can help amplify one's efforts and give reality to genius ideas.
Rank one.
You are almost always going to be given the benefit of the doubt if you are attractive and know how to carry yourself. This, in and of itself, is a social factor. Punishment is often less harsh on people seen as physically attractive (all offenses being equal), and attractive people are more likely to be hired in the first place.
Just look at most celebrities. The brains get blown out by the sunshine pumped up their rectums, and their social skills shrivel up and perish as people begin to seek them out simply for the chance to see them with their own eyes. Yet they are "successful" (so long as they have enough sense to quit while they are ahead and get out of the cameras before overdosing on drugs or developing severe psychological disorders).
Socialization is one of the most important amplifiers of any traits you have. The more people who know you're attractive, the more influence you command. The more people know you have a mind that makes a razor look dull, the more influence you have and the more opportunities you will have to turn that into a source of income (or the more likely you will be given opportunities to fulfill goals).
But that said, you must have something to bring to the table - something to make you worth socializing with (ability and attractiveness are something of a currency in socialization... everyone likes to introduce their beautiful and/or intelligent friends... though wealthy people and people who represent different circles of friends tend to be very powerful social contacts, as well).
So, it's really difficult to really say who is 'most likely' to be successful. I've known some stupid people who have known the right people and gotten into some very good positions (that they are actually good at... and, unfortunately, others who have gotten into positions they have no business being in - but they look pretty and/or have a nice ass and that's why they will never be fired).
Social skills are certainly the most important way to 'market' what you have.
But of "what you have" - being attractive is the most beneficial. Even beyond intelligence.
Though one is truly blessed to be both attractive and intelligent. Even if you are socially awkward, you will still end up developing friends and social connections (the socially awkward part is mostly in your head - and something you can learn to work around).
