There is no one-size-fits-all answer to what content sells on YouTube as it depends on your niche and audience. However, some popular genres include beauty, gaming, food, and vlogging. It's important to create content that is engaging, unique, and provides value to your viewers.
Consistency and authenticity are also key factors in building a successful channel. Ultimately, your content should align with your brand and cater to the interests of your target audience.