Of the presidential candidates announced so far, here're my current preferences, in order:
(1) Rand Paul
(2) Hillary Clinton
(3) Marco Rubio
(4) Ted Cruz (prejudiced, pseudo-"Constitutionalist," uber-religious asshole / NEVER)
When Jeb Bush enters, he's going to be tied with Rubio (and I'm sure, many others) in the "generic nothingness" category.
What I hope for Rand Paul is that he maintains his principled anti-interventionist stance and his principled libertarian, laissez-faire stance on social issues. If he swerves hard right, then there's no point to him.