We all know that G1 was closer to G4 in theme than the subsequent generations. We also know that the inspirations for our Mane 6 and several BGPonies grew from some of those original characters.
 
And that was as much as I cared about G1, until Aerial Aims Mod made a post about this pony right here. Thanks to that post, Heck Yeah Pony Scans, and some wiki diving, I can now officially declare that I have a favorite G1 pony.  
Majesty is probably the most brutal protagonist unicorns in the history of MLP. Her magic puts Twilight to shame, she could give Starswirl the Bearded a run for his bits, she can keep up with Zecoras rhyming, and her motherly instincts make Celestia look like a horrible ruler. She literally laughs as she employs downright villainous methods to defend her fellow ponies.  
And she doesnt mess around with friendship magic, or reformation, or trying to compromise, or reconciling differences. Majesty straight up giggles as she murders the creatures that threaten the peaceful denizens of G1 Equestria; she turns a goblin to stone forever, dissolves a small force of trolls into foam, and turns a witch into a tree. And all her spells have a rhyming sing-song to go with them.  
In G4 terms, her special talent appears to be Alteration and Transmutation magic. She alters physical reality and transmutes matter with a rhyme and twirl of her horn.  
With that kind of power and brutal sense of justice, its no wonder why her name is Majesty.  
(Design based on the original G1 Majesty toy)