PLA warps less and can be printed on an unheated surface (3M Blue Tape 2090). It is also a harder plastic, it has less flexibility than ABS and when it breaks it tends to shatter. PLA prints at about 180 degrees C and has a sweet smell (like burned sugar/waffles). PLA also prints wonderfully to either plain glass or Kapton heated to 60c.
PLA Plus <>
PETG <>
ABS prints best on a heated surface, kapton over aluminum or glass are popular choices. Without heat abs will curl up and ruin the print. ABS has a bit more flexibility than PLA. It prints between 200 and 230 degrees C and the smell bothers some people.
Alphabetized list of filaments & settings used.