I wasn't going to post this, but when I saw Tina's post about just diced-up beets, I thought I would. According to magazine I'm getting all these recipes from, roasting is the best way to cook beets - it brings out their natural sweetness.
Preheat oven to 425. Wrap 1 lb well-scrubbed beets in 2 or 3 packets of foil. Place on a baking sheet; bake until beets are slightly soft to the touch, 45 minutes to 1 hour depending on their size. Cool beets in packets, then rub off skins with paper towels (use a paring knife for tough spots).