Well I use to have a B&Q self propelled mower, and it was good, or so I thought at the time. Was £100 quid so thought it would last me a few years. I got 3 years out of it before it blew the crank. Was serviced too.
I've now bought a Viking MB248, it's made by Sthil and has a briggs & stratton engine and is infinitely better, real nice cut, doesn't have roller on the back but didn't need that, and with it being a push one it's lighter so the wife can use, more to the point she can even start it!! And comes with a 5 year warranty so long as serviced once a year. Cost me £219 from local lawn mower place.