FLStudio 12, which richly deserves to be number one in the recent Tech RADAR rankings.
Fully understand 12.4.2 is just out, so bugs are going to occur.
For me I have Softube's Amp package, and FLStudio crashes ...
FLStudio 11 (64-bit) in FL 12.0.2 (64-bit), on a Windows 8.1 64-bit OS for about four days now, and it crashes every single time. I have to force quit through Task Manager after a few minutes ...