Rufous Hummingbirds are especially fond of the nectar from bottlebrush shrubs. If at all possible, try to add these highly-prized shrubs to your hummingbird garden.
You can read more about the Rufous Hummingbird in the Backyard Birds section including a story about a Rufous Hummingbird with a bee on it's beak.
Check out the links to the Anna's Hummingbird and the Broad-tailed Hummingbird where you can read about them and watch videos of them.