Fair warning, this probably (definitely) wouldn't be my pick, buy my letter-obsessed boy loves Have Fun Teaching's Alphabet Songs.
There's a similarity to Yo Gabba Gabba, with the repetition and electronic music.
I played lots of nicer music I considered better quality, and, in his typical way, he responded "No," every time I said, "Do you like this?"
And then I played this. He stopped. He listened. And he said, "yes." Miracle of miracles. They also have an album of counting songs, if you're interested.
So here you have it, 27 songs from Have Fun Teaching: