Can't pick one. The Ghostbusters are at their best when they are together. When united, each of their personalities equal "the super nerd". Each ghostbuster is very one dimensional but this is why the films work so well. The group is a single person split into four. The ghostbusters equal what every nerd wants to grow up to be...,Peter-Popular, funny, witty charming, smart but also carefree. Ray-Child like innocence with a super IQ who is shielded by the truths of the world because he has never quite grown up and he can also fix anything. Egon-Sage like wisdom, a clear perspective (firm grip on reality), discipline and endless knowledge. Winston..,He's the take no shit badass that every nerd has inside of them.
So, i can't pick just one but i suppose, i would go with Egon because he is the smartest and most knowledgeable of the bunch. I'd probably have the most fun having a conversation with Egon or Ray.