If the Church wants to staunch the flow of younger people leaving religion, it would make sense to elect a Pope who's at least as liberal as Francis was. I get that the Catholic Church is never going to be a bastion of liberalism, but they at least need to be somewhat modern if they don't want
eight people leaving the Church for every one who joins. Cardinal Luis Antonio Tagle seems like a good fit, and being from the Philippines would likely help bolster Catholicism in that part of the world. He's also fairly liberal on many things, and he's young. Cardinal Pietro Parolin wouldn't be bad either, since he is supposedly very good with worldly affairs, which is needed at the moment. Cardinal Matteo Maria Zuppi could be good for the same reasons.
I know Trump has mentioned Cardinal Raymond Burke as his desired Pope. Unsurprisingly Burke is an asshole and likely has heretical views, specifically
Americanism. Burke would likely increase the number of people leaving the Church, although many of his ideas would take Catholicism back to its traditional roots. I can't see the Holy See electing an American though.