I can tell you what not to buy and that's a Husqavarna. I had one of those for the last 6 years and it's the biggest POS I have ever owned. I put about 20 mandrels on it over 6 years. I've replace pulleys, clutches, wire harnesses, safety switches, steering brackets, and rebuilt the deck at least 3 times. The friggin thing broke every time you cranked it. I hated that thing with a passion and nearly spent as much time fixing it as I did cutting grass with it.
My Dad has had a Husqvarna for about 6 years or so, too, and has the same troubles with the deck. The engine is solid, on it, but it seems like he replaces a mandrel at least once a week...I mean it's a CONSTANT and ongoing thing! Damn thing uses more mandrels than it does gas.