Will radio covers a lot of territory. I'm going to talk about amateur radio.
Heathkits were the model "T" and enabled tons of hams to afford a REAL radio.
Another rig that stands out is the old Radio Shack HTX-202 HT's. Radio Shack made the very first 2m HT that included a battery, antenna, dry cell battery case, charger, CTCSS (both encode/decode) & DTMF. There were NO options for that radio since they were all included. Not one of the other MFGs offered anything remotely like it since they loved selling the "options" for tons more money.
Heathkit & Radio Shack both upended the amateur radio market.
Would LOVE to know the total numbers though. I still work a ton of FT101(a,b,c,d,e,ee) ops

73
Jaye