Based on talent I want Ehlers or Nylander. They are both little guys but have high end skill. Nylander had the best season ever for a 17 year old in Sweden's 2nd division pro league, and he is just killing it against guys his age at the U18s. Head and shoulders above everyone else there which includes guys like Virtanen, Perlini, McCann, Fleury, Pastrnak and Kapanen. He also did pretty well in the elite league putting up 7 points in 22 games. IMO he is a Kadri type prospect without the edge. Insanely talented playmaker, but small and a lot of bad habits so he is raw at this point.
Ehlers just had an insane season, and if you can get a 17 year old 100 point CHL scorer at 8 you do it. Great, explosive player who isn't getting the credit he is due because of his size (same build as Kadri 6'0 160 pounds), Drouin and the fact he is Danish. The guy scored 50 goals this year and 100 points. Here is the list of other guys who have done that in recent history (last 5 years): Petan, Weal, Huberdeau, Drouin, Strome, Yakupov, Seguin. I'll take a change on that kind of talent any day.
I'm not a huge fan of some of the other guys. Perlini has skill, but taking a winger without high end talent in the top 10 seems like a waste to me. Virtanen has great goal scoring potential, but he is pretty one dimensional and lacks the hockey IQ and playmaking ability to drive a line. The goalscoring ability, and physical play though is a great combination. Ritchie, McCann and Fleury should be solid 2nd/3rd liner/pair guys at the NHL level, they are good, solid players, but again that seems like a waste in the top 10. Kapanen and Pastrnak are also little skilled wingers, but not in the same league as Ehlers and Nylander.
For me if Ehlers is there you take him.