Bernie Mac, aka uncle Bernie. He did a great job raising those kids

Tony Danza in who’s the boss

Uncle Jesse & Joey in full house. Yeah Danny was still around, but they all pitched in.

Uncle Phil.

Dude took in a late stage teenager with trauma issues that wasn’t very close to his household and helped guide that kid into adulthood and did so with love and support.

That’s how you fucking roll.

However he was a dad, just not Will’s dad, so that might not count.

If you wanna go strict, I think Mr Belvedere might hit the target

Uncle Iroh (Avatar: The Last Airbender) for me

Wasn’t actually a dad to anyone? Or wasn’t actually a dad to the main character?

Because if it’s the second, it’s Uncle Phil, no question.