I didn't watch Enterprise closely enough during its original run, thanks to Smallville. But now that I'm watching the series online (yay, Amazon Prime), I'm enjoying it. And I like Archer. He doesn't have the same guidance that his successors as captains of the Enterprise later have. It makes him interesting.
Trip is the one that makes me laugh the most. He seems like a fun guy to get to know, as does Archer, but maybe Trip's a little more fun.
T'Pol... I like her, but she can be a real pain in the posterior.