Kid Goku was cool, I liked his genuine way and acting on instincts, his simple mindset, which sometimes turned to be the solution, showing many times ppl overthink things. I liked 23rd Budokai teen/adult Goku too, there it was markable he had matured a lot, I remember watching the episode he appeared meeting Bulma and co. in the 23rd Budokai before Kuririn, Ten and Yamcha got there --- though the manga seemed way more lackluster, the anime added layers that made it more meaningful.
I'm regards to DBZ, I think Boo saga Goku. He seemed serious and thoughtful there, like when he cooled Piccolo down with logic when Bobbidi was trying to bait him and the kids to show up, a stark difference from his pretty immature/silly Super self imo.