I did a lot of my early programming on BASIC6, since I grew up nearby and my school gave us DCTS accounts. It was basically the same language as BASIC(1): variables could only be two digits long and the result of an IF/THEN could only be a GOTO. I still loved the language, even though it was objectively garbage compared to BASIC7 and BASIC8 which had already been developed. They had cool things like proper subroutines, and using them would probably have been a lot more fun. The interesting thing was that the language was actually compiled, not interpreted like crummy PC BASIC. This made it (relatively) screaming fast.
I wrote my first big program in BASIC6. It was a chat application called ECHO that was a clone of something called Xcalibur that the college kids used. It was awful spaghetti code. I remember using up line number 10,000 and panicking because I could no longer find intermediate line numbers in big chunks of the code (I started counting by 10s and then gradually filled in a lot of the intervening lines. There was no renumbering procedure I was aware of.) All that speed came in handy since there was no concept of threading in BASIC6 and my program had to sequentially handle commands from all the users. People hated it with a burning passion.
One time I found John Kemeny’s email and showed him my amazing BASIC6 monstrosity. He wasn’t very happy about that.