Date someone long enough and you'll end up in Hawaii. Maui is great for slow hikes, and Oahu is fine if you're toting a tribe of kids, but, at 4,028 square miles, the Big Island offers what none of the others can: variety. Stay at one of Kona Village Resort's Polynesian-style bungalows (from $610; konavillage.com), where the resort's 82 oceanfront acres have everything you need. Rent a car anyway: The island is home to one of the planet's best drive-up stargazing spots, 13,796-foot Mauna Kea (ifa.hawaii.edu/mko). If it's a beach day, head to the eastern shore and hike down the access road into the Waipio Valley, where one mile of black sand awaits. And on the last night, grab a six-pack, drive down the dirt path past the Upolu airport to the low volcanic cliffs on the north shore and watch breaching humpbacks ply the channel as the sun sets. And rises.