Wiggy and I both use Extron. They're rack-mounted devices so they're big, but for $80ish you can get 16 port ones on ebay.
The inputs are BNC and support component, composite, and s-video. I've not had RF work on mine however. They're full matrix switchers, so if you have 2 TVs, you can run on system to one, and a second system to the other, or show the same system on both. Great for head-to-head playstation games with link cables for example. You do, however, need RCA -> BNC adapters or S-Video -> BNC adapters for most.