If your leagues values goals more, or is H2H with stats categories such as G, PPG, GWG, then Vanek is definitely your man.
If it's straight points, I would go with Hemsky. Although he's had some injuries slowing him down I just like the situation in Edmonton with Hall, Paajarvi and Eberle coming in. As early as this year you might see Hemsky explode.
Vanek is top six in Buffalo, but he still doesn't get huge minutes.
10 Team H2H Points-based Keeper League
G, A, PIM, SOG, +/-
W, SO, SV, GA
C: H. Sedin, Stamkos, Backstrom, Duchene, Granlund
LW: D. Sedin, Landeskog, B. Schenn, Tatar, Boedker
RW: P. Kane, Voracek, Hudler, Silfverberg, Toffoli
D: Ehrhoff, Edler, Franson, Del Zotto, Myers, R. Ellis, Hamonic
G: Quick, Bishop, Holtby, Peters, M. Jones
Farm: Terevainen, Nurse, Raanta
League Champion: 2009, 2011, 2013 and 2014
12 Team Roto Dynasty League Champion: 2011 and 2013