Amazing! I've never heard such a moving story! This is truly a beautiful tale among beautiful tales!

Literal

Amazing is! This-kind-of moving [attr-な] story [topic-は] first-time is! Truly beautiful-tale [gen-の] inside [gen-の] beautiful-tale is!

An enthusiastic reaction, stacking superlatives. 感動的 ('moving, touching') is the な-adjective form of 感動 ('emotional impact'). 美談 ('beautiful tale / uplifting story') is a literary noun for inspirational narratives. 美談の中の美談 ('a beautiful tale among beautiful tales') is a productive emphatic structure: '[category]の中の[category]' = 'the ultimate X / the peak X.' The stacked sentence-final ですs give it a formal but effusive tone.