Hi from a new kid on the block!

As a one time guitar repairer I would echo what others have already said ...if you have a vintage instrument try to keep the originals or replace with similar tuners. Otherwise I have excellent experience with both Gotohs and Schallers on more recent instruments...the Gotohs are somewhat cheaper and good quality if cost is the main concern. My current instruments are all Gotoh or Scaller-equipped.