Of all your gear, what piece impresses you most?

I like all my gear, yet the single piece that blows me away the most is my phono preamp.
We all acknowledge every component is important for overall system success. Staying within theĀ  theme of this thread I'll say my SET amplifiers in a "photo finish" win over my line stage.
I think as we move forward, it is typically the latest addition that we like most. Perfectly reasonable, in my estimation.

I don't make that many changes over time and my system stays the same for 2 or 3 years before I try to get to the next level. My speakers and preamp are over 10 years old; the SACD player 3 years old; and the power amps a couple of years old.

With that preamble, my amps do impress me greatly, probably more than the other components. I did not think they would improve the sound as much as they did. I was wrong.

Lamm ML2.1 SETs

Purchased a PBN groovemaster, with sme 312s tonearm, and I can't believe the increase in performance it gives me.