What's your favorite third pary lens?

Voigtländer 110mm f2.5 Macro APO-Lanthar.

When I had D7200 my favorite was sigma 50-100 f1.8, now all dx sold except the AFP 70-300 dx VR which surprisingly working on FX with some caveats

Voigtlander APO Lanthar 50mm f/2…

This is only a short list:
40 f/2.8 Kilfitt Makro Kilar
50 f/2.8 Schneider Super Angulon PC/TS
55 f/1.4 Zeiss Otus
75 f/1.5 Zeiss Biotar, Version 3
85 f/1.4 Zeiss Otus
90 f/2.8 Kilfitt Makro Kilar
200 f/3.5 Novoflex Noflexar Follow Focus
300 f/5.6 Novoflex Noflexar
500 f/5.6 Kilfitt Zoomar Sport-Reflectar

Maybe favorites, at least the most often used...

Rodenstock Apo Sironar Digital 135mm f/5.6
Schneider Apo-Digitar M 120mm f/5.6

That's a heavy rig.

Two lenses that really make my D500 shine are the Tokina AT-X Pro 14-20mm f/2 and Sigma 50-100mm f/1.8 Art. Indeed, there are things they do that beat some of my equivalent D850 options.

I tried the Tamron 24-70mm f/2.8 g2. Really nice image quality on my D800, but the AF was too slow so I opted for the Nikon AF-S NIKKOR 24-70mm f/2.8G which has blazing fast AF but lots of image quality issues. For my purposes, I'll take the fast AF on my zooms, which includes a similarly image quality flawed Nikon AF-S NIKKOR 70-200mm f/2.8G VR (yes, the first one).

Voigtländer APO-LANTHAR 35mm F2 Aspherical is by far my favorite lens.

Minor Mosque, Tashkent

HAND.