For me, I'm a big fan of iconic design. I think of watches as functional jewelry, so I like the ones with a design that is long-standing and specific to a company. This applies in lots of different ways to each brand, Big Eye for Longines to Royal Oak for AP. I value accuracy of the watch, so the closer it keeps time to 0 seconds gained or lost a day is better for me! This being said I love hearing my watch tick, and watching it sweep so must me mechanical.
Within these criteria there are a lot of options and you'll discover quickly the price range affects what a good watch is for you. A 500 dollar piece with a micro rotor might be what really gets you going but you also might see the value in a 1500 dollar piece with a funky bezel that's unique to the brand. It all depends, it should be fun that's the main thing.
Second hand longines