I think this may fit here better than in the self defense and fitness forum as this is more specific to knife use.  If anyone here practices knife combatives, either western or asian, please chime in with your system and what type of knves you prefer.  I train Manaois Escrima and also have training in Modern Arnis and Silat.  Being Active Duty Army I also do some military combatives, including knife use.  Besides the FMA stuff I train in I also have extensive training in Korean Tang Soo Do, Hapkido, and Aikido.  My favorite combative knives are an old school SOG Government and even more old school Gerber MK II.  I also own  several Randalls and find the #1 and #2 to be almost perfect fighting knives.  Although at close to $500 a pop now I leave the Randalls in the knife case.  I also have an ongoing love affair with the Cold Steel Tanto and find this knife works very well in FMA knife techniques.  I brought my SOG, Gerber, and Tanto to Iraq with me and carried them all at one time or another along with a Spyderco Police, A SOG Flash II, and a Buck/Strider 880SP.  Although I was lucky to never have to resort to knife combatives, I did find the Tanto very useful in cutting the restraints off detainees after transporting them to our TDHA.