Canons are know for their replacable printhead*, but as with all inkjets, frequent use helps keep them in good shape but be sure to clean up where the head sits when off every once in a while. If the seal starts to get gunked up then the ink will begin to dry in the microtubes and clog the head.
well I have a few good printers laying around. I have a lexmark and and hp deskjet not being used. My everyday printer is a HP Deskjet 970CXi professional inkjet. I bought it in 2002 and I think it has a current page count of 35,000 and still going strong. I absolutely love it, mostly because of its duplexer (fully automatic double sided prints) I hope my next daily use printer is as good as this one.