What is a Good Printer for Linux?

mystik asks: "What would be a good printer for my linux system? I bought an HP712C for a great price, but was disappointed to find out that HP made the Protocol propriatary, and unanable to work without some siginificant hacking of my linux system. Hopefully I can get some good printers cheap... " Well, this is a rather broad question. It would help if folks would recommend several different printers covering as many of the printer classes (ie dot-matrix, bubble-jet, ink-jet, and lasers) as you can.