Ka'anapali has numerous resorts and is near the touristy, but still attractive, town of Lahaina.

Kahului has the airport and a good spot for windsurfing, but not much else. Not the place to stay on vacation.

Kihei is filled with cheap condos. It's near Wailea, but not very attractive, IMHO.

Wailea has wonderful resorts and puts you closer to some of my favorite spots in Upcountry.

I would stay in either Wailea or Ka'anapali