One of my favorite hockey tournaments to watch is the World Junior Championship taking place right now in the Czech Republic. It features the best under 20 year-olds from 10 countries. A majority of the players, particularly from the US and Canada, will play in the NHL someday. Some of which are already drafted and/or signed by NHL teams. If you are already a fan of an NHL team and want to know which players might play for your team someday, here is a simple guide for figuring out who to watch on which teams.
Note: a lot of this data was cobbled together from data of different sources (i.e. IIHF Rosters, eliteprospects.com, NHL.com, etc.). Spellings across these sources can be particularly inconsistent for non-North America countries. There are probably errors. If you see something, please point it out. Also note that some counties rosters are not complete. several countries will add players to their rosters in the coming days.
Here are some other interesting data points.