+1 for fit - don't be seduced away by flashy marketing or nice brand logo's - if it isn't a close but comfortable fit then it won't do the job it is designed for which is to keep a thin layer of water next to your skin with minimal flushing.
Decide what thickness you need based on the water temps you will dive, then try the available ones on and narrow down to fit. After fit think about the function, and pick the one from those that fit which suit you best, padded/re-inforced knees and elbows, front or rear zip and so on according to what you want/need.
You will need to think about your type of diving and preferences before you go so you don't get confused or railroaded once there.
Have fun and enjoy - happy new year ! - Phil