It depends on different factors-How much $$ you have or deals offered at time of sale, longevity, acreage, size of mower, do you plan on just using it for mowing or will you use implements(means difference between getting a garden tractor vs yard tractor)? Comfort, cut quality, obstacles or slopes in yard? Ease of operations and maintenance.
Those things must be looked at as there are a lot of good brands now. It used to be the more $$ you spend the better but thats not true. You can spend 5,000 plus or 1100 plus and both will get the job done for years.
I have a Husvarna 24 hp 48 inch more since 2005(15 years almost and 500 hours)-its been bullet proof, only replaced the mower deck belt and battery once. Only thing to break was the throttle linkage which I welded myself.
Some have had issues with Husqvarna but so does any and every other brand. Big box stores or dealers the machine will be exactly the same accept the deck options. Manufactured decks are preferred over stamped on all brands and almost all brands offer both. Stamped is a thinner material and can rust out, bend or break easier but is lighter than the thicker manufactured decks.
Go test drive them and with a budget in mind, good sales people will ask you the right questions like acreage, if you have slopes etc...and make recommendations on models. Dont worry about brands so much.
Comparing Kawasaki vs kohler vs Briggs and Stratten is like racing fully loaded dump trucks. They all do very well and all have week and strong points. Comparing gas vs diesel is a much better point. Mine is 24hp but I will never come close to need that kind of HP from a yard tractor.
I am looking at the Cub Cadet ZT with 4 wheel steering next because of my slopes and all the obstacles I have to negotiate. If other brands offer the same I will check them out too.