I'm very much a fan of Medaka Box, and I think that for something that is essentially a parody for shonen shows and their ridiculous power systems it is one of my favorites in that category and far beyond the likes of series like OPM due to Nisio still adding that high quality touch of character writing and development (I'm looking at you Kumagawa) though personally I don't think I'd ever put it (or any other Nisio work) above Monogatari imo.