We have a lawnboy pushmower (I think we got it in the early 80s) that we had to send in to the shop one time, but it has otherwise been great. We've also had a ton of off-brand push mowers around the farms over the years... none of them work any more (OK - I might be able to coax the one back to life - It's a Rally, I think) for various reasons.
<sigh> As for riding mowers, our 1986 (IIRC) John Deere has been awesome. In that time, we've also killed a Rally, a Cub Cadet, a John Deere (from the late 60s), and a Craftsman. We do a lot of lawn mowing, across three farms, and one residential lot. At the moment the John Deere is being hauled to all of our locations, because the Cub Cadet that we were using for two of them just decided to malfunction (I don't know what's wrong with it, but I know that my Dad and Brother messed around with it for a few hours, and then told me to bring the John Deere up to that farm as well).