Hey guys you know I've watched BB alot and I'm starting to think that Walt is more evil than Gus is.
In Season 4 yes Gus is the main antagonist but a majority of the reasons why he stated to hate Walt is Walt's fault.
Walt was the one who told Jesse to expand their territory when they were street dealing and this is what caued Combo's death and who lead to the whole fiasco with Jesse wanting to kill the Rival Dealers and eventually to Gus hating Walt! Gus had a right to want to kill both Jesse and Walt as killing the dealers could've exposed his empire as did killing Gale.
And of course Walt is the one who told Hank to keep investigating Gale which finally did expose Gus' true nature and empire and Walt killing him did nothing but cause disaster and exposed a whole empire of criminals that coul've exposed Walt!
I honestly can't stand Walt! He is prideful, arrogent and truely evil! The only reason he became a drug dealer was to satisfy his ego and he put his enire family in danger and ruined countless lives! He poisons a child just to manipulate Jesse, he let Jane die to gain control of Jesse and he got Hank killed.
Depends on how you look at it. You can definitely make a good argument for Walt being more evil than Fring, that is for sure. I view Fring as more evil due to the nature of Fring's motivation being more creepy and chilling than Walt's motivation. At the very least we understand Walt and can maybe on some level relate to him and feel some level of empathy or at very least, sympathy, for Walt in some of the things he goes through. Walt is the quintessential underachiever. He ended up as a high school chemistry teacher living in the heart of suburbia somewhere in Albuquerque, New Mexico.
He does it to prove himself to himself. His ego, as you implied, is out of control. But with Gus... sure some part of what he does is out of pride and arrogance, like Walt, but we are basically told through the show that Fring's motivation is largely and mainly financial. Even his killing of Don Eladio, which could be used as evidence for Fring's pride and arrogance because of his need for vengeance for his late partner, was mainly to gain control of the market and deliver a major hit to his competitors.
That, coupled with Fring's emotionless mannerisms tells me that Fring is cold. Maybe even like a sociopath. Fring is this mysterious character whose background we know so little about that will do absolutely anything for financial gain. He will allow children to get killed as long as business isn't interrupted, as we see the killing of Tomas. As we know, Walt was shown to be okay with directly hurting children... but we also see moments of weakness in Walt, moments where he falters and begins to examine his actions and what he's become.
Fring is simply cold and apathetic to most people dying and in some cases will kill individuals himself, as we see in episodes like Box Cutter. Even when he does, it is more to prove a point and it is done with the same aloofness we are accustomed to seeing with everything else he does. Walt is certainly evil, but I don't know if I'd consider him even as evil as Gus. That's just me.