General Purpose Coarse-Grained Force Field 
Check out this paper, a nice example of how metadynamics can be combined with Martini for efficient sampling of protein-protein binding free energies:
M. Lelimousin, V. Limongelli, and M.S.P. Sansom. Conformational changes in the epidermal growth factor receptor: role of the transmembrane domain investigated by Coarse-Grained metadynamics free energy calculations. J. Am. Chem. Soc., Just Accepted. doi:10.1021/jacs.6b05602
The team of Prof. Vogel has developed a fix to prevent side chains from flipping to the wrong side of beta strands. Soon to be implemented in martinize. For details, see:
F.A. Herzog, L. Braun, I. Schoen, V. Vogel. Improved side chain dynamics in Martini simulations of protein-lipid interfaces. JCTC, online. doi:10.1021/acs.jctc.6b00122
A nice study by Wang and Deserno show that the pivotal plane in a Martini DMPC bilayer is located closer to the bilayer center in comparison to an atomistic bilayer. This has important consequences for the interpretation of the effect of curvature on membrane properties. For details, please consult the full paper:
X. Wang, M. Deserno. Determining the tilt modulus by simulating membrane buckles. JPCB, online. doi: 10.1021/acs.jpcb.6b02016
Curious to see what a crowded membrane really looks like? Check out Clement's masterpiece:
C. Arnarez, S.J. Marrink, X. Periole. Molecular mechanism of cardiolipin-mediated assembly of respiratory chain supercomplexes. Chem. Sci., 2016, online. doi: 10.1039/C5SC04664E
We published a perspective on computational modeling (computational 'microscopy') of cell membranes in the imaging series of the Journal of Cell Science:
H.I. Ingólfsson, C. Arnarez, X. Periole, S.J. Marrink. Computational 'microscopy' of cellular membranes.
J. Cell Science, 2016,
Keep your membranes fluid: New parameters for cholesterol, ergosterol, and hopanoids
M.N. Melo, H.I. Ingólfsson, S.J. Marrink. Parameters for Martini sterols and hopanoids based on a virtual-site description. JCP, 143, 243152 (2015); http://dx.doi.org/10.1063/1.4937783