I did not make this post, all credit goes to Quickshot76, as he made the original post on the One Punch Man Wikia. If you want to talk about this further, I would suggest finding the original page and consulting him there, as commenting here would not do much. I do not take any ownership for this post.
"Alright. I've heard a lot of contriversy on if Saitama could beat Goku. And I am here to tell you today, that Satiama would Goku, and anyone.
I'm going to go with Saitama's feats. Also, I'm not counting the dream sequence. Anyways, let's start with Marugori. Saitama jumps up, and slams his fist into Marugori's cheek, most likely breaking his jaw. I would say his neck, considering on how far in flew back, but that's just me. Marugori can add up to about Vegeta at 24,000 when he first came to Earth. This is as low as I can go, besides full power Nappa, which probably isn't the case.
The Beast King. I can add him up to around Vegeta's full power on Earth when he was using his final move. With a bored look on his face, Saitama easily kills him with with the Normal Consecutive Punches. Beast King's top body is completely ripped off, either completely destroyed or just flew off the camera view. I really doubt Saitama was trying.
Carnage. Carnage's normal form probably adds up to Frieza's 2nd form at full power, and Carnage's Carnage mode is probably around Frieza's final form at 25% power, at the most. Now, Saitama was clearly panicing at the time about the bargain sale at the store. He wasn't paying attention at ALL at Carnage, taking all the hits Carnage threw.
Now, let me just mention his sparring with Genos. Now, Genos is extremely powerful. He's no pushover. But, Saitama took him like nothing. When Genos wanted Saitama to take him seriously So, Saitama throws a punch. Now, I'm going to say he was using about 50% of his power. I'll get to this later, because if he used 100%, even with that force, Genos would either fly back, have his face get ripped off, or die completely. Now, back to the force. Saitama threw a punch, then stopped, having Genos' hair fly back. As he turns around, he sees that the force competely penetrated a mountain. Now, if you look off into the distance, you see OTHER mountains destroyed. And they're from far away from the original mountain you see. Now, that could either be a valley, or an opening, but considering the shape, it was most likely from Saitama.
Alright, here's a biggie. The Deep Sea King. (DSK). A few S Class heroes fought DSK, and were completely outmatched. They both ended on the ground, on the verge of death. Especially Genos. Genos is probably in the top 5 of strongest S Class heroes, and even though he had a good fight, he still lost. Then, Saitama came up. Clearly bored, and fed up with DSK for almost killing his student, he just wants to get it over with. The DSK hits Saitama, and he doesn't really care. He takes it like a champ. The DSK goes for another attack, but Saitama punches him. Destroying him. COMPLETELY. This isn't the only thing. When Saitama hits him, the force of his punch throws back all the rain and clouds. All of them. Nothing more to say about that.
Here it is. Boros. Boros is probably Majin Buu at his first form of power, and Full Power Boros is probably around Kid Buu Level., due to their destructive abilities. Now, the fight is pretty self-explanatory, besides when Saitama brings his "final move," Saitama parts the clouds completely on the world. Moving on. But the good stuff is what Boros says at the end of the fight. When Boros mentions it was hard fought, Saitama replies with, "It was." It's what Boros says next. "You lie." Boros clearly can tell when someone is powerful, so he can tell Saitama is off his charts. Saitama had strength to spare, stated by Boros. Saitama obviously more powerful than anyone. While this is great proof, there is one more humongous piece of information.
In the OPM web comic, it is stated by the infamous Dr. Genus, that Saitama has "removed his limiter." Even though Saitama is a human, he has surpassed his limiter to getting stronger, while Goku still has that. As a Saiyan, Goku has a very, very big limiter. Giant, probably the biggest one, considering he can always get stronger. He can undergo transformations. But, still, he has a limiter. Saitama is a human, so he has a short one. But, he surpassed it. I say, it's like a cliff. A steep one. You can get to one point where you've hiked cannot surpass. To the point where you kind of just give up, or keep on trying, and get nowhere. Is what NORMAL humans would do. Saitama is no normal human. He has climbed past the the cliff. And, at that point, its just the trail you need to walk along. I would say that, considering Saitama's strength thus far, he surpassed his limiter either a year, half a year, or two years into his training. Now, Dragon Ball fans. Hear me out. I like Dragon Ball too, but you can't ignore the facts. As much as Goku can improve, even get to the power level of Googleplex, nothing can beat the power of Infinity.
Well, thanks reading my rant."
All credit goes to Quickshot76.