The Dragon Ball series is definitely a series with a heavy focus on surpassing the most powerful fighter. It's arguable that the series wouldn't move at all without these characters wanting to become more powerful than the next guy. If you've been following the series for the past century you'll find that no one is attempted to be surpassed more than the main character Goku.
Throughout Dragon Ball, countless heroes and villains alike have the goal of surpassing and defeating Goku. While many have failed some are still in the running to be able to accomplish this feature. That's what we'll be looking at through this list.
10 KRILLIN: FAILED
How could Goku's oldest rival not make the list right? These two best friends practically grew up together under the watchful eye of Master Roshi himself. During this time growing up together, Goku and Krillin underwent the same training from the Turtle Hermit and constantly tried to surpass each other.
As we all know, that rivalry really didn't last long. Around the ending arcs of the original Dragon Ball series and the beginning of Dragon Ball Z Goku had truly reached another level that Krillin couldn't dream of reaching. The rivalry and dreams of surpassing Goku may have ended but their friendship still goes on.
9 CUNBER: CAN SURPASS
Is this character non-canon or is he from another universe of Dragon Ball? Well, we're not fully sure but we know that this evil Saiyan has the potential to surpass Goku, as he did in the Super Dragon Ball Heroes anime and manga series. He is one of the main reoccurring antagonists in that spinoff series as well.
His potential to surpass Goku is seen throughout his battle with him and Vegeta during the Dragon Ball Heroes Prison Planet and Universal Conflict saga. During these sagas he goes toe-to-toe with both Saiyans and pushes them to have to fuse into Vegito Blue to stand a chance against his true power.
8 YAMCHA: FAILED
Well, duh. This has got to be the most obvious failure when it comes to trying to surpass Goku. Yamcha wasn't always such a joke you know. He can very well be seen as the first opponent that Goku met his match again during his run-in with him and Bulma during his bandit origins. Funny enough Yamcha just about took Goku to his limit until he was caught off guard by the beautiful Bulma. He used to be a very bashful guy around women.
Since then Yamcha has stepped down from the competitive spotlight and now he enjoys a life of relaxation and luxury.
7 BROLY: CAN SURPASS
Anyone that caught the amazing Dragon Ball Super: Broly film knows this for a fact. The new rendition of Broly made for the new Dragon Ball series can easily keep up with Goku and he made it known during his big bout with the legendary Super Saiyan of Earth. This battle pushed Goku to his limits and made him have to go as far as to learning the fusion technique with Vegeta to keep up.
If the feats Broly accomplished in this film didn't convince you that he could surpass Goku, we're not sure what will.
6 TENSHINHAN: FAILED
Much like Yamcha and Krillin, Tenshinhan was one of Goku's old rivals in the original Dragon Ball series and pushed Goku to the limit back when they battled during his childhood. In fact he came pretty darn close during their first battle and even used his life-threatening technique, Tri-Beam, against him, albeit after a warning so he was sure Goku wouldn't be killed by the massive attack.
Goku has since then far surpassed the three-eyed warrior and left Tenshinhan no chance at catching up.
5 MAJIN BUU: CAN SURPASS
One of the most powerful Z-Warriors and one of the most powerful fighters in the Dragon Ball world period. As seen during his originating saga, Majin Buu is a fighter with limitless potential. He is able to continuously grow and can even train to further his power as seen in Dragon Ball Super when he became skinny Buu and went head-to-head in a sparring match with Goku.
Goku has constantly acknowledged Majin Buu's limitless power and considers him a formidable foe and ally.
4 PICCOLO: FAILED
Same story as the past warriors mentioned that can't keep up with Goku sadly. Piccolo was one of Goku's most powerful rivals back in the original Dragon Ball series. He made his appearance near the end of the series and much like his father pushed Goku far enough to make it seem as if he was actually going to win.
These two's rivalry lasted until the battle against Raditz and the Saiyans in the Dragon Ball Z era. After this saga although Piccolo kept training, once Goku reached Super Saiyan there was just about no way for the demonic Namekian to keep up.
3 ANDROID 17: CAN SURPASS
Android 17 wasn't thought to be strong enough to even be in the same league as Goku until his newfound enhancements in Dragon Ball Super. By enhancements we mean left-field pull but that's a discussion for another article. Back to the main topic, Android 17's potential to surpass Goku wasn't just seen during their sparring session but throughout the Universe Survival Saga's battles as well, where he had a hand in saving the universe.
This potential comes as a perk to being an android and possessing limitless power.
2 FRIEZA: FAILED
He's tried and tried again with each attempt resulting in failure. Frieza is Goku's lifelong arch-enemy as the two have had bad blood since before Goku was even born. Ever since Goku's initial surpassing of Frieza's power level after his Super Saiyan transformation during their fated battle on Planet Namek, Frieza has done nothing but try to up Goku.
However, Frieza has come close recently with his new Golden Frieza transformation. He definitely put Goku's new skills and God transformation to the test.
1 GOHAN: CAN SURPASS
From the start of Dragon Ball Z series, it was shown that Goku's son, Son Gohan, had the potential to surpass his father. In fact, that character progression was originally supposed to be the main point of this extension to the Dragon Ball universe. It has since been changed from being the focus but Gohan is still continuously teased to have the ability to surpass his father's power.
Maybe one day we'll see Gohan finally become more powerful than his father as he did back in the fight with Cell and during the Mystic Gohan appearance and stay that way. Until then we'll have to wait.