All of them are good though! The OS outfit stands out because of its flow- the open vest is pretty neat and made him look like an "adventurous" kid. However, AG gave Ash the hood, and that is cool. I kind of wished he actually used it- it's like his clothes are stationary or something. DP was a bit more mature (like the series itself hurhur), though like AG, his vest could've mimicked OS and could've been opened to add more movement to his character. He seemed a bit rigid in some scenes. Also the vest design makes him look like a Totodile..
I also dislike the design of the "original hat". : c But that has always just been me.
The AG gloves looked the coolest with that black and glow-green. : D I'm not sure about the hat, he should've gone with Hilbert's.
He should've just worn Hilbert's whole outfit. Just because it's the best Pokemon Trainer design since Red.