1 - Jean Jacques Burnel's bass on the track "Peaches". I heard it and thought, ooh, that's really cool.
2 - Sting with The Police. I saw him on TV and thought "bass sounds great, and he looks cool".
3- my brother pkayed 6 string (after he decided to learn on the acoustic I was bought for Christmas when I was around 12, but which I never used), so I decided to pick uo the 4 stringer instead at age 15.
At age 17, I saw The Police live on stage - New Year's Eve 1981, at Edinburgh's Ingliston Exhibition Centre. The bassist in the support band (Jools Holland just after he had left Squeeze to fo his own thing) was an unknown player who blew my mind. The player? Pino Palladino - he changed my whole perception of what a bassist could be.