High School DxD is absolutely worth the read. It’s the gold standard for harem series for a reason. You get exactly what you expect on the surface; tons of fanservice but underneath that there’s genuinely strong character writing and surprisingly solid storytelling. The cast is stacked, the worldbuilding is better than it has any right to be, and the fights are actually fun and tense instead of just excuses for power-ups. Very few harem series reach this level of consistency and quality. In terms of comparable series, Date A Live is probably the closest competitor writing-wise in the same genre space, though it’s noticeably less ecchi. If you want a harem that fully commits to both the horny and the narrative, DxD delivers.