Anything was frightening when compared. Iris was not particularly bad; she was decent enough as a person. But if Barry really chose her, then if there were some competition for whose wife was the most outstanding, he would probably rank second to last in the Justice League.
Aquaman would undoubtedly be dead last, because Mera's personality was truly awful. Her head was filled with opposition between Atlanteans and land-dwellers. She simply was not on the same wavelength as everyone else.
Superman's wife, Lois, needed no further explanation. She was the model of a virtuous wife and loving mother. No one could compare to her feelings for Clark, and she lacked neither courage nor intelligence. Even Luthor sometimes respected her opinion.
Green Lantern Hal's fiancée, Carol, was a Star Sapphire of the Violet Lantern Corps and also a Justice League member. Setting everything else aside, simply being recognized by the Violet Lantern Corps meant no one could doubt her love for Hal. At most, she just had a few more true loves at the same time.
Green Arrow's wife, Dinah Lance, the Justice League's Black Canary, had abilities and a sense of justice beyond question. She and Oliver were comrades-in-arms as well as lovers. Their breakups and reconciliations did not change that.
The same went for Martian Manhunter and Hawkgirl's current situation. As two of the Seven Leaders, they could be considered a couple blessed with a lifetime of happiness.
Cyborg did not have a girlfriend yet, nor could he find one for the time being. After all, there was still an octopus down there. Shazam, meanwhile, was just a brat. He did not even know what having a girlfriend meant.
Batwoman's situation was rather special. Su Ming was not quite sure whether she loved Catwoman or Joker. It was better