As a kid I had little battery powered Casio synths, but the first professional synth that I got to touch was a Yamaha DX7 in my junior high band room. It was made of metal, had some design qualities like a Lamborghini, and had a patch that sounded like a motor cycle. It made quite an impression!
Here is a video of me playing one I owned recently:
As an adult, I still appreciate the industrial design of the original DX7. Even more, I appreciate the way the timbre of the sounds in this synth respond to your playing. The FM sounds respond so musically to velocity. It remains one of the best synths for playing live in my opinion. It has a fantastic attack.
Soon after I bought this DX7 last year, I came across a Yamaha TX216 module at a swap meet. It has the exact same signal path / sound as the original DX7, but there are several of them in a rack (3 in my unit). Since my contemporary keyboard controllers are higher quality than the original DX7 keyboard, I resold the DX7 but I am planning on keeping the rack version. I look forward to making some videos that share how I use the 3 instances together. It definitely holds up against the other synths in my collection
Though it often has a controversial reputation in the synth community, the DX7 will always be one of my favorites.