When I bought my 1st embroidery machine back in 2000, I bought a batch of 75/11 embroidery needles at 100 in the batch. Then I started ordering 80/12 when I could find them and then 90/14. Also specilty needles for jeans, leather, metallics, etc. I use whatever needle depending on the thread I'm using whether it's for embroidery or for quilting. This is for my combo embroidery machine.
For the quilting machine I order size 16, 18 and 20, again depending on the thread I'm using. Think is Schmetz 135x5