Riding mower all the way, anything else is a waste of you life. If you really want a push more, don't get a self propelled. My experience is that the drive system always has a lot of drag when you aren't using it, and they need more maintenance than riding mowers do. And the reason I bring the drag while not in use up, is that they are NEVER fast enough. I don't like spending an hour mowing <1 acre.....LAME!!
You can change your driving patter on a riding mower just as you can with a push mower. And in about 15 minutes your finished mowing, grab the weed eater, spend another 10-15 and you're done.
If you have a really busy yard like I did at my last place, a push mower will be better suited. But if it's more open than not, get a riding mower and have a couple extra beers with the time you save from not walking ever square foot of the yard.
I'll also second buying older mowers. New ones are all definitely crap. Yeah, you can spend $8K on a John Deere of a Cub Cadet, or you can spend $200-400 on a Wheel Horse, Case, or some other brand from the 70s-80s that has Hydrostatic drive and you might worry about your kids totalling your car with the mower. They are built with heavy gauge steel beam frames. The Hydro-drive allow for variable speed selection, easy to go from forward to reverse, and they never stop working.
Bates 4000, 80gb Ram, Quad Port 900 Processor, DVK compatible memory card, Dual burning DVD drive, 16000 CTC combo drive, with a +4 Digital upgrade card.