Earlier quoted context omitted.
Numenor alone has enough to make a good series - you've got epic characters, great events, powerful kings, beauty, love, treachery, doom, magic, battles, betrayal and ruin. I've seen decent series done on much less than that.
Beren and Luthien would make a fantastic tale as well. Disguising themselves as a vampire and a werewolf to steal a Silmaril from Morgoth in the pits of Angband? Makes the quest of Mt Doom look like a picnic. Pity we'll never see it
And the fall of Gondolin. And the Children of Húrin. Though not with a happy ending, both of them.
Still, Gondolin has a great journey, love, betrayal, and an epic siege with mechanical dragons and balrogs.
Húrin is more of a greek tragedy than an American TV series, but I'd still love it.