My new Symphonic Line Kraft 250 Class A monos. I dunno about for life, but for the next decade or maybe more I could see them staying seated in my system. Deep, powerful but refined bass without excess fat, purity in the mids, and detailed without any fatigue in the highs. Macro dynamics are of course great as they should be with this level of amp, but their micro dynamics are incredible.
They are extremely powerful high current amps that drive my large 86db sensitivity Revel Salon 2s to concert SPLs while maintaining dynamics, tonal balance and detail throughout the volume dial. Despite the manufacturer's listing a putative 250 watts into 8 ohms output, they play much louder than the 310 wpc Plinius SB-301 they replaced (a damn good amp in its own right). They are also very fast and play without any overhang but without sounding the least bit clinical.
In the end, while I'm describing gear attributes here, all this leads to a place where late at night I can close my eyes and hear musicians making music and not pay any attention to the stereo. I feel pretty lucky being able to do that.