“Wow factor”... for me that really limits it to Deccas and real cost-no-object MCs, the Koetsu, top-level Lyra, vdH or Ortofon stuff. None being things I’ve personally owned.
The most ‘esoteric’ or up-market I’ve ever run was a rather disappointing used Dynavector XX-1L (just boring), and a Lyra Lydian B, which I liked as it was very dynamic and engaging, but it seemed to wear faster than I’d expect from a cart of that price-class. Aside from that I’ve tended to live in the ‘good all-rounder’ area of the market with thing like Ortofon MC20FL, Audio Techinica OC9, AT33PTG, Denon DL-110 etc. Just good value carts that don’t disappoint, but don’t have the astonishing dynamic ability of Deccas or the huge natural soundstage of the very best MCs. I’ve a lot of time for the humble DL-103, but I can’t actually live with one due to the conical tip, same goes for the conical SPUs, which again I love in many areas.
A lot of my fondest memories are actually with the better MM carts of the 70s and early-80s before aggressive MC marketing from Linn, Haymarket and others basically killed or diminished the format. The Shure V15, Grace F9E, Fidelity Research FR-101, Ortofon M25FL, Glanz etc etc. Some really great cartridges that exist in a totally different mindset of low mass, high tracking/tracing ability etc. I really like this era of carts, though again I view them in the ‘good all-rounder’ rather than “wow!” class, as is my current Nagaoka MP-500, which really dates from this period (it’s little more than a re-badged 1970s MP-50). A cartridge I’m running because it tracks everything with astonishing ease and clarity and matches both my deck/arm and phono stage well (neither being as easy as one might think due to the cast-iron platter and a valve phono stage that doesn’t seem to like low capacitance MMs). The MP-500 just doesn’t do anything badly at all, so quite a ‘grown-up’s’ long-term cartridge rather than something that would knock anyone out on a short dealer dem. Not a “wow” cartridge, but certainly a very good one - I’m sufficiently happy with it that I have a sealed spare stylus awaiting, and that is something I very seldom do.