Like everyone here, I've had a number of portables. The most notable are/were:
Pioneer RK-888 (still own this. I even have the tape displayed in the picture!)- Amazing cassette section, great sound and awesome tuner. One of the first portables with Type II recording ability.
Pioneer SK-71 (or 72, might have been a Pacific derivative product, I forget)- Awesome sounding, soft-touch control. These had a defect where playing source material with a fair amount of bass would get into the transport and cause audible intermodulation distortion. But still a sweet-sounding piece. Don't own this anymore.
Aiwa CS-880- Massive, was 400 bucks back in 1980! Passive radiator, amazing, deep bass, unbelievable sound. Soft-touch controls, one of the first metal-capable portables. Still own this.
Sony CFD-5- The first portable CD player boombox. APM speakers, great sound, nice full-logic deck. One of my all-time favorite portables. Still own this.
Oh, those were the days!