It's really difficult to say what the "best" is as it's really a matter of opinion. For me, I'm an enchi freak, so I'd have to throw enchi something.. Unless I wanted to start a recessive project.. Then I'd go ultramel or pied. How about you say what you like?

What you could also do is look at WOBP, and see what combos you could make with what you currently have. Then go for those!