It's unfortunate that Mike Bossy's career was cut short due to injury, as he was one of the most prolific goals scorers in NHL history. In 9 of his 10 seasons Bossy recorded at least 50 goals, 9 consecutive seasons to start his career. In his 10th and final season, he managed 38 goals in 63 games. In 5 seasons Bossy scored over 60 goals.

Wayne Gretzky had 9 50 goals seasons during his 20 year career. Mario Lemieux had 6 50 goal season in his 17 year career, though it would have been higher is many of season weren't cut short due to injury. Alex Ovechkin has scored more than 50 goals 3 times so far in his 4 year career.

NHL 50 Goal Seasons
#	Player	Team(s)	Games	Seaons
9	Mike Bossy	New York Islanders (1977/78 - 1986/87)	752	10
9	Wayne Gretzky	Edmonton Oilers (1979/80 - 1987/88) Los Angeles Kings (1988/89 - 1995/96) St. Louis Blues (1995/96) New York Rangers (1996/97 - 1998/99)	1487	20
6	Guy Lafleur	Montreal Canadiens (1971/72 - 1984/85) New York Rangers (1988/89) Quebec Nordiques (1989/90 - 1990/91)	1127	17
6	Marcel Dionne	Detroit Red Wings (1971/72 - 1974/75) Los Angeles Kings (1975/76 - 1986/87) New York Rangers (1986/87 - 1988/89)	1348	18
6	Mario Lemieux	Pittsburgh Penguins (1984/85 - 1996/97, 2000/01 - 2003/04, 2005/06)	915	17
5	Bobby Hull	Chicago Blackhawks (1957/58 - 1971/72) Winnipeg Jets (1979/80) Hartford Whalers (1979/80)	1063	16
5	Brett Hull	Calgary Flames (1986/87 - 1987/88) St. Louis Blues (1987/88 - 1997/98) Dallas Stars (1998/99 - 2000/01) Detroit Red Wings (2001/02 - 2003/04) Phoenix Coyotes (2005/06)	1269	19
5	Pavel Bure	Vancouver Canucks (1991/92 - 1997/98) Florida Panthers (1998/99 - 2001/02) New York Rangers (2001/02 - 2002/03	702	12
5	Phil Esposito	Chicago Blackhawks (1963/64 - 1966/67) Boston Bruins (1967/68 - 1975/76) New York Rangers (1975/76 - 1980/81)	1282	18
5	Steve Yzerman	Detroit Red Wings (1983/94 - 2005/06)	1514	22
4	Jari Kurri	Edmonton Oilers (1980/81 - 1989/90) Los Angeles Kings (1991/92 - 1995/96) New York Rangers (1995/96) Mighty Ducks of Anaheim (1996/97) Colorado Avalanche (1997/98)	1251	17
4	Michel Goulet	Quebec Nordiques (1979/80 - 1989/90) Chicago Blackhawks (1989/90 - 1993/94)	1089	15
4	Tim Kerr	Philadelphia Flyers (1980/81 - 1990/91) New York Rangers (1991/92) Hartford Whalers (1992/93)	655	13
3	*Alexander Ovechkin	Washington Capitals (2005/06 - present)	315	4
3	Cam Neely	Vancouver Canucks (1983/84 - 1985/86) Boston Bruins (1986/87 - 1995/96)	726	13
3	Jaromir Jagr	Pittsburgh Penguins (1990/91 - 2000/01) Washington Capitals (2001/02 - 2003/04) New York Rangers (2003/04, 2005/06 - 2007/08)	1273	17
3	John LeClair	Montreal Canadiens (1990/91 - 1994/95) Philadelphia Flyers (1994/95 - 2003/04) Pittsburgh Penguins (2005/06 - 2006/07)	967	16
3	Luc Robitaille	Los Angeles Kings (1986/87 - 1993/94) Pittsburgh Penguins (1994/95) New York Rangers (1995/96 - 1996/97) Los Angeles Kings (1997/98 - 2000/01) Detroit Red Wings (2001/02 - 2002/03) Los Angeles Kings (2003/04, 2005/06)	1431	19
3	Rick Vaive	Vancouver Canucks (1979/80) Toronto Maple Leafs (1979/80 - 1986/87) Chicago Blackhawks (1987/88 - 1988/89) Buffalo Sabres (1988/89 - 1991/92)	876	13
3	*Teemu Selanne	Winnipeg Jets (1992/93 - 1995/96) Mighty Ducks of Anaheim (1995/96 - 2000/01) San Jose Sharks (2000/01 - 2002/03) Colorado Avalanche (2003/04) Anaheim Ducks (2005/06 - present)	1067	16
2	Alexander Mogilny	Buffalo Sabres (1989/90 - 1994/95) Vancouver Canucks (1995/96 - 1999/00) New Jersey Devils (1999/00 - 2000/01) Toronto Maple Leafs (2001/02 - 2003/04) New Jersey Devils (2005/06)	990	16
2	Blaine Stoughton	Pittsburgh Penguins (1973/74) Toronto Maple Leafs (1974/75 - 1975/76) Hartford Whalers (1979/80 - 1983/84) New York Rangers (1983/84)	526	8
2	*Brendan Shanahan	New Jersey Devils (1987/88 - 1990/91) St. Louis Blues (1991/92 - 1994/95) Hartford Whalers (1995/96 - 1996/97) Detroit Red Wings (1996/97 - 2003/04, 2005/06) New York Rangers (2006/07 - 2007-08) New Jersey Devils (2008-09)	1490	21
2	Danny Gare	Buffalo Sabres (1974/75 - 1981/82) Detroit Red Wings (1981/82 - 1985/86) Edmonton Oilers (1986/87)	827	13
2	*Dany Heatley	Atlanta Thrashers (2001/02 - 2003/04) Ottawa Senators (2004/05 - present)	495	7
2	Dave Andreychuk	Buffalo Sabres (1982/83 - 1992/93) Toronto Maple Leafs (1992/93 - 1995/96) New Jersey Devils (1995/96 - 1998/99) Boston Bruins (1999/00) Colorado Avalanche (1999/00) Buffalo Sabres (2000/01) Tampa Bay Lightning (2001/02 - 2003/04, 2005/06)	1639	23
2	Dennis Maruk	California Golden Seals (1975/76) Cleveland Barons (1976/77 - 1977/78) Minnesota North Stars (1978/79) Washington Capitals (1978/79 - 1982/83) Minnesota North Starts (1983/84 - 1988/89)	888	14
2	Dino Ciccarelli	Minnesota North Stars (1980/81 - 1988/89) Washington Capitals (1988/89 - 1991/92) Detroit Red Wings (1992/93 - 1995/96) Tampa Bay Lightning (1996/97 - 1997/98) Florida Panthers (1997/98 - 1998/99)	1232	19
2	Glenn Anderson	Edmonton Oilers (1980/81 - 1990/91) Toronto Maple Leafs (1991/92 - 1993/94) New York Rangers (1993/94) St. Louis Blues (1994/95, 1995/96) Edmonton Oilers (1995/96)	1129	16
2	*Ilya Kovalchuk	Atlanta Thrashers (2001/02 - present)	534	7
2	*Jarome Iginla	Calgary Flames (1996/97 - present)	930	12
2	*Jeremy Roenick	Chicago Blackhawks (1988/89 - 1995/96) Phoenix Coyotes (1996/97 - 2000/01) Philadelphia Flyers (2001/02 - 2003/04) Los Angeles Kings (2005/06) Phoenix Coyotes (2006/07) San Jose Sharks (2007/08 - present)	1321	20
2	Joe Nieuwendyk	Calgary Flames (1986/87 - 1994/95) Dallas Stars (1995/96 - 2001/02) New Jersey Devils (2001/02 - 2002/03) Toronto Maple Leafs (2003/04) Florida Panthers (2005/06 - 2006/07)	1257	20
2	*Joe Sakic	Quebec Nordiques (1988/89 - 1994/95) Colorado Avalanche (1995/96 - 2003/04, 2005/06 - present)	1363	20
2	*Keith Tkachuk	Winnipeg Jets (1991/92 - 1995/96) Phoenix Coyotes (1996/97 - 2000/01) St. Louis Blues (2000/01 - 2003/04, 2005/06 - 2006/07) Atlanta Thrashers (2006/07) St. Louis Blues (2007/08 - present)	1055	17
2	Kevin Stevens	Pittsburgh Penguins (1987/88 - 1994/95) Boston Bruins (1995/96) Los Angeles Kings (1995/96 - 1996/97) New York Rangers (1997/98 - 1999/00) Philadelphia Flyers (2000/01) Pittsburgh Penguins (2000/01 - 2001/02)	874	15
2	Michey Redmond	Montreal Canadiens (1967/68 - 1970/71) Detroit Red Wings (1970/71 - 1975/76)	538	9
2	Pat LaFontaine	New York Islanders (1983/84 - 1990/91) Buffalo Sabres (1991/92 - 1996/97) New York Rangers (1997/98)	865	15
2	Peter Bondra	Washington Capitals (1990/91 - 2003/04) Ottawa Senators (2003/04) Atlanta Thrashers (2005/06) Chicago Blackhawks (2006/07)	1081	16
2	Pierre Larouche	Pittsburgh Penguins (1974/75 - 1977/78) Montreal Canadiens (1977/78 - 1981/82) Hartford Whalers (1981/82 - 1982/83) New York Rangers (1983/84 - 1987/88)	812	14
2	Reggie Leach	Boston Bruins (1970/71 - 1971/72) California Golden Seals (1971/72 - 1973/74) Philadelphia Flyers (1974/75 - 1981/82) Detroit Red Wings (1982/83)	934	13
2	Rick Martin	Buffalo Sabres (1971/72 - 1980/81) Los Angeles Kings (1980/81 - 1981/82)	685	11
2	Stephane Richer	Montreal Canadiens (1984/85 - 1990/91) New Jersey Devils (1991/92 - 1995/96) Montreal Canadieans (1996/97 - 1997/98) Tampa Bay Lightning (1997/98 - 1999/00) St. Louis Blues (1999/00) Pittsburgh Penguins (2001/02) New Jersey Devils (2001/02)	1054	17