1st and 4th mower are basically the same. Made by MTD and just rebadged to Sears and Cub Cadet
2nd and 5th are basically the same as well. Made by Husqvarna and rebadged for Sears.
I think JD are overpriced for what they are so no opinion on it.
So what I will say about these mowers is that the MTD forum gets a lot more traffic than Husqvarna does. But they both get traffic so there are problems with both mostly with bad gas we have to buy anymore. If you want trouble free(at least as trouble free as possible) Buy ethanol free gas and nothing else if possible.