I think he is the friendliest. He is gentle and nice, when he gave the bread and protect them when the prince was going to hit them. He would be a a great sultan.

he's a people person...well if they give him a chance

or Prince Eric because they are the two princes who had the most interactions with people.

Most of the princes are basically loners, including Aladdin.

Eric and John Smith are the only ones who hang out with a bunch of guys. But John Smith doesn't have any close friend, while Eric's pretty close to Grimsby. Eric is also friendly with Ariel even though he's smitten by "the one".

Or Eric.

Eric nearly died for his pat, Max. He is also seems good at communications and gets alone pretty well with a mute Ariel, he instantly realizes she needs his help and offers her that help. Aladdin is also up there, because he is the only one who decided to set Genie free like no one else did before and while at some point he wanted to be selfish about it and leave his one last wish for himself, in the end, after him and Genie become true close friends and Aladdin appreciated everything Genie did for him, he willingly risks to lose his last chance with Jasmine for the sake of keeping his promise.

and also Eric

i'd say

he almost died for Thomas and saved him twice, and he is popular (as Ractliffe claimed) to all men.
if you can't see it... then ugh...

He's friendly and down to earth because he didn't grow up in royalty. He can easily relate to everybody and is very kind

same as princessld

He is open-minded, and warm-hearted, even to animals. Most of all, he is a fun guy.

when he first met ariel you could tell she was freaking him out but he was still so warm hearted and king!