It depends on the day lol. I have a lot of harnesses. My favorite things to have in a harness for walking are:
1) a ring at the rear so the leash stays out from under the dog.
2) something easy to get on and off.
3) the right length for the dog. I like the leash to attach about 2/3 of the way back from the base of the neck, towards the butt. Too far forward and you have to be on your game to keep the leash out from under the dog. Too far back and it's strange for the dog because even small amounts of pressure will pull their rear around.
My favorite is a harness I got from Vohne Liche Kennels. I haven't found another exactly like it. I have a couple from Elite K9 that I like. One particularly on longer dogs. I can get the models if you are interested.
I own 2 cheap, no name puppy harnesses, a RuffWear with a backpack, and 7-8 tactical harnesses from the usual companies. I don't like how the RuffWear goes on, because it has a strap that goes between the front legs. I prefer just a simple chest strap for a walking harness. Over the head, snap 2 buckles on the chest and belly straps and go. The RuffWear is built really cheap compared to the tactical harnesses, but it was priced accordingly.
I guess I'm spoiled. I have some really nice harnesses with cobra buckles and very high build quality. They were very expensive, but I needed jump ratings and something that would never break during a mission. You can certainly spend far less on a harness and have just as much fun with your dog!