I was never able to find one that stuck to the side of my machine that I was happy with. They never stuck for good, and the vibration of the machine made the light bounce around. But I did find this one from IKEA that I love. I love it so much I bought 2 more, one for a friend and one as a backup for myself. Lol.
http://www.ikea.com/us/en/catalog/products/20169658/
It comes in different colors and models - this table-top model, a clamp-on model, and a larger one that sits on the floor instead of the table. I really like it because it's flexible enough to move, but stiff enough to stay where I put it.