Traits of a Good Forechecker-
1) Players keep their feet active, and stop on destinations (checks or pucks).
2) Players understand their forechecking system and can read and reacte to their specific role within that system.
3) Players understand their place on the ice isn't necessarily where the puck is, but where the puck is going to be, and where they are on the ice in relation to the opposing players.
4) Players make themselves occupy more space than their size dictates by taking good angles to the play and keeping active sticks.
5) Players play on the defensive side of the puck, communicate and support their teams to create narrow windows and force turnovers.
Bleacher Report Ranked the 20 best forechecking forwards in the NHL-
http://bleacherreport.com/articles/533428-nhl-power-rankings-20-best-forechecking-forwards-in-the-nhl
20. Patrick Marleau
19. Shane Doan
18. Brendan Morrow
17. Rene Bourque
16. Jordan Staal
15. Dustin Brown
14. Ryan Malone
13. Curtis Glencross
12. Rick Nash
11. Chris Stewart
10. Corey Perry
9. Mike Richards
8. Henrik Sedin
7. Jonathan Toews
6. Henrik Zetterberg
5. Cal Clutterbuck
4. Alex Ovechkin
3. Milan Lucic
2. Pavel Datsyuk
1. Sidney Crosby
Personally, I'd have to throw in two NJ Devils as well- Adam Henrique and Patrik Elias and a former Devil Zach Parise
All these players are used in penalty kill situations, and have tremendous Hockey IQ's, and work ethics.
Keith Acton, one of the best forecheckers and most underrated penalty killers in the history of the NHL, has this great video-