>>9189565MOTU sold over 1.5 billion toys between 1983 to 1989
Transformers only did about 600 million toy sales between 1984 and 1990
Joe was even harder to find data but multiple sources say 400 million toys sold from 1983 to 2004 just when the relaunch occur
Thundaercats is a complete mess with very little data or recordings of sales but I can at least find they made 250 million toy sales in 1985
So taking OPs question at it's word the "biggest toyline" was MOTU
That said Im sure demographically we all had our own experiences
