Here's the top 56 "half seasons" in terms of adjusted PPG from '94 to '12. ES GF/GA ratio with player on the ice and On/Off ratios are also listed. For comparison with Crosby's 2010-11 half season, it's important to remember that those ratios are for the full season, so in each player's best 41+ game stretch that season, it's very likely that their ratios were often significantly higher as well. Amazingly, Crosby's 2011 is the 18th best of the 55 player-half seasons in adjusted PPG and also both 18th/55 in ES GF/GA ratio and On/Off ratio. Again, considering that the ratios for other players are for full seasons, Crosby's ranking (among these 55 half seasons) would likely be lower if compared to those players' half season ratios. This would seem to contradict the notion that his half season was more outstanding due to "all around" play, rather than pure offensive brilliance (no surprise there, honestly). There are also other factors to consider: quality of linemates, defense/goaltending, off-ice comparisons, and the fact that forwards can control offensive portion more than defensive portion of the ratios. Crosby did not have the best linemates and had Malkin's line as part of off-ice comparison, neither of which helps him much.
| | HS | FS | FS
PLAYER | Year | PPG | GF/GA | On/Off
Lemieux | 1996 | 2.54 | 1.20 | 0.99
Jagr | 2001 | 2.01 | 1.40 | 1.34
Jagr | 1996 | 1.98 | 1.50 | 1.44
Lemieux | 1997 | 1.94 | 1.47 | 1.97
Jagr | 2000 | 1.94 | 1.68 | 2.03
Lemieux | 2001 | 1.90 | 1.51 | 1.39
Lemieux | 2003 | 1.89 | 0.70 | 0.46
Selanne | 1999 | 1.88 | 1.53 | 2.50
Jagr | 1999 | 1.85 | 1.37 | 1.70
Forsberg | 2003 | 1.83 | 2.47 | 2.55
Lindros | 1999 | 1.82 | 2.05 | 2.36
Crosby | 2007 | 1.82 | 1.45 | 1.64
Ovechkin | 2010 | 1.80 | 2.34 | 1.89
Francis | 1996 | 1.80 | 1.46 | 1.33
Lindros | 1997 | 1.76 | 1.85 | 1.64
Jagr | 1998 | 1.76 | 1.56 | 1.63
Ovechkin | 2008 | 1.75 | 1.59 | 1.97
Crosby | 2011 | 1.74 | 1.79 | 1.82
Gretzky | 1994 | 1.74 | 0.76 | 0.88
Malkin | 2012 | 1.73 | 1.46 | 1.42
Sakic | 2001 | 1.70 | 2.28 | 2.10
Jagr | 1997 | 1.69 | 1.47 | 1.88
Malkin | 2008 | 1.68 | 1.44 | 1.44
LeClair | 1999 | 1.67 | 2.27 | 1.78
Thornton | 2003 | 1.66 | 1.32 | 1.39
Alfredsson | 2008 | 1.65 | 1.24 | 1.21
Fedorov | 1994 | 1.64 | 1.77 | 1.60
Lindros | 1995 | 1.63 | 2.11 | 2.66
Crosby | 2010 | 1.62 | 1.31 | 1.45
Thornton | 2006 | 1.62 | 1.78 | 2.63
Kariya | 1997 | 1.61 | 2.06 | 2.57
Thornton | 2007 | 1.61 | 1.60 | 1.78
Malkin | 2009 | 1.61 | 1.46 | 1.44
SedinH | 2010 | 1.59 | 1.62 | 1.61
Selanne | 1997 | 1.58 | 1.67 | 1.96
Forsberg | 2001 | 1.57 | 1.93 | 1.46
Kovalchuk | 2006 | 1.57 | 1.04 | 1.00
Ovechkin | 2009 | 1.57 | 1.28 | 1.22
Bure | 2001 | 1.56 | 1.10 | 1.60
Sakic | 2000 | 1.55 | 1.82 | 1.91
LeClair | 1997 | 1.55 | 1.98 | 2.37
Alfredsson | 2006 | 1.55 | 1.85 | 1.32
Lindros | 1996 | 1.55 | 1.47 | 1.17
Forsberg | 2004 | 1.55 | 2.25 | 2.10
Jagr | 2006 | 1.54 | 1.92 | 1.94
Bure | 2000 | 1.54 | 1.48 | 1.46
Forsberg | 1998 | 1.54 | 1.23 | 1.29
Bure | 1994 | 1.53 | 1.10 | 1.16
St. Louis | 2007 | 1.51 | 1.16 | 1.74
Gretzky | 1998 | 1.51 | 0.97 | 1.34
Iginla | 2007 | 1.51 | 1.26 | 1.03
Selanne | 1996 | 1.50 | 1.22 | 1.43
Jagr | 1995 | 1.50 | 1.71 | 1.78
Elias | 2001 | 1.50 | 2.27 | 1.78
Fedorov | 1996 | 1.49 | 2.44 | 1.77
Forsberg | 1999 | 1.49 | 1.87 | 1.91
MEAN | | 1.68 | 1.60 | 1.67
MEDIAN | | 1.63 | 1.51 | 1.63
Not sure how far back those stats go, and doubt they would change the On/Off numbers very much for non-shutdown forwards.