A few guys off the top of my head:
Harrison Barnes
DeAngelo Russell
Jabari Parker
Demar Derozan
TJ Warren
In all honesty I think its Giannis. He looks like he's finally made the leap to superstardom. His stats across the board are all better than they were last year (Outside of 3-pt FG%) and what he brings is incredibly rare. What's really standing out to me the most though is that he looks like he's ready to be a leader. If the game's on the line, he takes over. He has the killer instinct that the best players in this league have. Milwaukee could very well be a top 3 team in the east right now if it weren't for Middleton's injury. Giannis has done a phenomenal job holding the fort for them while he's been out.