Maui suggestions?

I've been to Maui once before, for five days. Going there again soon, again for 5 days, with someone who's never been. So I have some ideas of what to see and do, and I asked a friend who lives there for some more, but if you've ever been there, I'd love to hear what you liked?

Sadly on this trip we'll miss the Kahului Swap Meet / farmers market, which is on Saturday mornings, because we're arriving Saturday late afternoon :(