My best mover by far was an unraced TB mare (bought her as a yearling) by Zodiac (Speak John x Pole Star, by Northern Dancer), out of Super Saint (Boldwood X Go Saints Go, by Royal Stepper). People came out of the woodwork wherever we went asking about that mare.
From my (admittedly limited) experience, I’ve come to associate Speak John with wonderful minds and all over strength and athleticism; Northern Dancers with more lightness (and lightening quickness that can come out of nowhere) and beautiful, efficient movement; Bold Ruler with classic good looks and ability (Boldwood in particular for elegance.)
That mare was my ideal type of horse: she had enough suspension, a flat enough knee, and length of stride to blow 'em away wherever she went: 9’s on gaits from the likes of Sue Blinks and Hilda Gurney, and BN hunter trainers offering to ride her for free in exchange for first option to buy.
First horse to come along with movement to impresses me that much is Hush-- WB (of course :() by Compliment. Boy, do I wish we could find and make more of such TB treasures!