That series was such a specific, joyful flavor, wasn't it? If you're hunting for that same blend of chaotic ensemble comedy and surprisingly soft heart, 'Monthly Girls' Nozaki-kun' is my first recommendation. It skewers shoujo tropes with the same affection Ouran did, but from the perspective of a clueless manga artist and the girl who develops a crush on him. The side cast is just as gloriously unhinged. Gintama is the other obvious pick if you want pure, fourth-wall-demolishing parody energy, though its length and occasional tonal shifts into serious arcs can be intimidating.
For something with a similar 'found family' vibe among a group of beautiful misfits, 'SK8 the Infinity' fits oddly well, despite being about skateboarding. The over-the-top rivalries and character dynamics are pure comedy gold. And if you miss the reverse-harem setup but want it dialed to an even more ridiculous extreme, 'Kiss Him, Not Me!' is basically that same joke played straight, with a fujoshi protagonist surrounded by handsome guys.