Emil, from NieR: Automata. You probably think I'm kidding. Listen to this and then tell me that isn't the cutest thing you've ever heard: Cute personality > cute appearance. Considering the crapsack world of NieR and all the stuff Emil goes through in the first game, that only makes stuff like this all the more adorable.
To me, Kirby is the perfect combination of both cuteness and badassery. I didn't know that combination was possible until I found out about Kirby. Rock on, pink puffball.
Let's see.. Sephiroth. How is he cute? xD Big giant wing that, has an obsession with the planet. Don't people love that stuff?
The Lumas from Super Mario Galaxy I mean, just look at it! Spoiler The little noises they make are super cute as well.
Honestly, I'm gonna go with probably the most obscure choice so far: Staffy, or as he's known in America, Starfy. (Even though Mario and Luigi very clearly advertised his game with the original name in English) It was the first time I ever used the seal form with him. That sounds he makes when in that form is the most adorable thing ever.
My friends hate my obsession with Quaggans from Guild Wars 2. I think they're adorable! They're sort of like a mix between a Quagsire and a whale. Spoiler: These guys