Clean, Complex & Tasteful
Named after it's now well-liked originator, the tasteful Jeffrey Eldredge, the Eldredge knot is going to be one of your favorites once you learn it. I first learned the original Eldredge, which is a bit less polished than this, the revised Eldredge - the revised is also a cleaner result. I've included a link to the original below the video so you can get a grasp of where it came from.
A note on the Eldredge is that it works best with a solid color tie, which emphasizes the pattern of the knot. You can also try striped tie, but wider stripes will diminish the impact of the knot. Patterns make the knot less easy to notice and the whole purpose of tying an unusual knot will be lost.
Here's a link to the original Eldredge video, the one that started it all.