I would say speakers I've had for 22 years would be qualify as a pretty good investment, and those would be a combination of the amazing 10" driver Innovative audio Cabinet speakers and Sub-table and the equally amazing Acoustic Research Phantom 8.3 low slung surround speakers.
More recently would be the Oppo 205 of course, the best Blu-Ray player ever made even even today it can't be matched because of some of its features and even the DAC was state of the art six years ago (and still used in current components)
Last but not least is the glorious Audio Research MP1 100% analog multi-channel preamp. This thing is built like a tank with a circuit board that looks like it was constructed by hand with individual daughter board per channel--and sounds equally sensational. As long as I stay in the far superior sounding analog world, it's not going anywhere!
And finally for headphones, the drop-dead gorgeous titanium-infused Final Sudio Sonorous X cans that look is good as they sound. One of the most underrated products ever released in my opinion.