If I were to list them all, I'd be listing over 100 different series, so I'll just mention a few I find comparable to DB that haven't been mentioned in this thread yet.
JoJo's Bizarre Adventure - Helped shape the landscape of modern Shonen as much as DB did, heavily inspiring more strategic Shonen such as Hunter X Hunter.
Kinnikuman - Can be considered the series that laid the foundations of traditional Shonen storytelling before DB popularised such conventions even further, to an extent I find it hard to imagine Toriyama wasn't in some way inspired by Kinnikuman. After all, it did such story lines as a super strong alien protagonist, constantly stronger foes, transition from comedy to battles and even a power level system long before DB even began.
Yu Yu Hakusho - Many of it's concepts were obviously inspired by DB once it transitioned fully into a battle Shonen, especially towards the end of the Black Chapter Arc. I'd say it's slightly better than DB due to employing better strategy/ability usage and having more complexity in it's villains, though the Three Kings Arc is a far worse final arc than the Boo Arc. It can be considered dated due to Hunter X Hunter pulling off it's best concepts far better, though it's at least infinitely better than the ripoff of it known as Bleach.
Saint Seiya - Both were extremely popular Shonen series in the 80s with roots in some ancient culture (China's Journey to the West for DB and Greek Mythology for SS). I'd say Dragon Ball is better though since Saint Seiya's plot can be pretty generic at times, with the main appeal having more to do with the mythology and character designs.
Toriko - Pretty obvious how much inspiration it took from DB with Toriko's attire and many of the energy attacks in the series. Dragon Ball is overall better than it though, considering DB at least had some good points after it's timeskip into DBZ. Can't really recommend the series now.
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