When I travel to Maui I like to stay in a condo in Kihei. I love that it gives you the feeling as if you are living there. Where we stay, they provide BBQ picnic areas in the middle yard which is a great way to save money and meet new fellow travellers at dinner. Kamaole beach is across the street and local stores are walking distance.
Lahaina is a great place to spend the day. I love scoping out all the neat shops where local artists reside and some famous ones too (my fav: Peter Lik). We always make sure to grab lunch while we are in Lahaina. The drive from Kihei is beautiful with a look out point on the way. Driving beside the ocean makes the ride go by so quickly.
One thing I say I'm going to do each time and miss the chance is Surfing! I think next time I go I won't leave till my butt gets out on the water with a board. Surfing helps building muscles in your arms (paddling), your legs (squatting on the board) and your abs (balancing on the board). What a great way to get some exercise! I have though been snorkeling in Maui and truly enjoyed swimming with the exotic fishes.
If you are looking for a great place to go with your partner or vacation with the family, I highly recommend Maui.