Kikimaru said: Name me a non-sexy Rider (hint: you can't)
it depends on your definition, but I would say Rider in Fate/Prototype is the closest answer to your question, after considering every possible type(Femme-fatale-kind, BRO-GAR-kind and the mixture of those two, at least).
Kikimaru said: Name me a non-sexy Rider (hint: you can't)
Rider of Fate/strange fake instantly comes to my mind, he's a creepy shadow-like being that is clearly not sexy. No human form, just... a thing... made out of shadow.