There's no fixed answer. Consider your budget, water quality, and availability of the filter and parts. Screen filters are generally the least expensive. If you have a city water supply with nothing more than a periodic grain of sand or flake of rust in it, a screen filter will be fine in most cases.
Disk filters are good at removing particulates, like sand, and organic matter. A disk filter consists of a stack of round disks. The face of each disk is covered with various sized small bumps, and each bump has a sharp point on the top of it, somewhat like a tiny pyramid. The bumps create tiny spaces between the discs when they're stacked together. The water is forced between the disks, and the particulates are filtered out because they won't fit through these gaps. The sharp points on the bumps snag the organics. For automatic cleaning of the filter, the disks separate from each other, freeing the debris, which flushes out through a flush outlet. With less expensive disk filters, you must remove the disks and hose them off.
