I've used Makerbot (for ABS), MakerGear (for ABS and PLA), Ultimachine (for PLA) and Protoparadigm (for PLA).
Of all the plastic I've used the only things I dislike are:
- Anything not on a spool. I won't buy that way any more. In particular a 5lb bundle of 1.75mm PLA from Ultimachine was mostly wasted due to tangles, despite care in handling it.
- The black PLA from Ultimachine was much runnier and harder to work with than other PLA. The best printing PLA I've used so far is silver from Protoparadigm.
Protoparadigm is very close to me so I get quick shipping.
All of the ABS I've used has been much more consistent than the PLA in how it prints.