A very enjoyable 4th class route on the west side of the moutain
Find your way to Mule Pass and then onwards to Finger Lakes just below Burro Pass. From there hike up to the pass, turn left and have at it.
The best way to do this route is to stay with the ridge in as direct a way as possible. Typical of Sierra ridge routes, you can make it as hard as you like. The line I took had a few steep sections, but it's a ridge route so generally speaking it's pretty low angle. The route has been done many times, but I suspect most folks trend right into the sandy gully that makes a better descent route than a way to go up.
No particular gear requirements. I did the route in Salewa Rapace boots which are much like LaSportiva Trangos
Trip report: http://esa-rol.com/content/gallery/71/matterhorn-west-ridge