I am the least coordinated person in the history of ever, and I love the elliptical. LOVE. And it's easier on my feet and knees than anything else, too, which is a bonus. Start on the least elaborate one, hold on tight, and don't worry-- everyone has one good "I fell off the elliptical" machine story, and you won't have more than one, because once you get it, you're totally fine.

The machines at my crappy Y have target heart ranges on them, which is handy since I don't remember things.