there are various meanings of denpa. Sometimes it's used for so called "akiba-kei" like https://youtu.be/d1qILv7Jp98 as an example of denpasong. but then denpa also can mean psychological mind break like subahibi cross†channel or chaos;head are denpa VNs. Even though the term "denpa" is highly debated in that context as well, it means something like psychological horror involving delusions and eroguro nonsense. i think cross†channel is a great vn. When it comes to anime and manga, the term isn't used as much so it's hard to say. There are obviously shows like denpa onna to seishun otoko or denpa kyoushi which are called denpa in the name? Maybe welcome to the nhk would be the most denpa-like anime / LN. If you look at "denpa" interest stacks on MAL, some people take it to mean the psycholical delusional horror and include nhk chaos head eva and stuff (eva is definitely not denpa btw), but then there is a list with moetan and digi charat and things which are "hyper moe" over the top cute psychosis like denpa-song. So which denpa do you preffer?