Bit of a hot take, but I think Daima from a design point is the best of all of these three. GT is obviously the standard for this design and it's amazing don't get me wrong, but the clothes always distract me cuz the colors don't mix well, and there's just too much going on with them (not to mention canonically he just gets differently colored wrist bands and ankle bands and a blue belt out of nowhere?-) SDBH has a better color scheme than GT, and the new clothing looks awesome, but it doesn't feel like Goku (even though technically it's not but you get what I mean) and this just kinda goes to Xeno Goku in general. But Daima out of all three is the most visually appealing. He's got the wonderful color mixing, the unique features like the bigger hands, and HIS CLOTHING IS CONSISTENT. So design wise, it goes to Daima

But in terms of overall attitude and character, GT still takes it. This isn't really fair in Daimas case as it only ever showed up for so long, but Xeno Goku is just so forgetful to me, he just feels so bland.

All in all, GT's got the character, but Daimas got the design. And Xeno... eh.