Chuunibyou demo Koi ga Shitai!, Kono Subarashii Sekai ni Shukufuku wo! Recommendations
I feel like both shows are similar in a lot of ways. The most obvious is that Megumin and Rikka are the same character. The tone of both shows is mostly light hearted. The sort of childish, over the top, delusional, battle scenes that briefly took place in chuunibyou is fully realized in konosuba as a full blown fantasy rpg. The main difference is that chuunibyou is a romance, while konosuba is a distinctive ecchi comedy.
Both have chuunibyou main characters.
Both of the chuunis are treated, and act like children at times and act quite adorably.
Both have plenty of comedy elements but KonoSuba is more of a Comedy Chuunibyou.
The chuunibyou tenancies in Chuunibyou play a much more important role while in KonoSuba they're more for a comedic effect.