I love writing and taking notes in pencil. I love the erasability, and the sense of depth that comes with being able to shade and scratch. But the two most important things about a writing instrument are that it works and that it feels comfortable in my hand. On those two metrics, nothing compares to the Zebra M-301 mechanical pencil. (At least at its price point)
The Japan-based pen and pencil manufacturer, Zebra, is known for high quality at a very affordable price. My Zebra mechanical pencils never break on me, and rarely get jammed up. If you're looking for an entry-level mechanical pencil, there's none better.