it is very difficult to answer a so general question, because it depends on your application needs. As you have put your question under the topic CFD Simulation, I am not the best person to answer it, because I work with Electromagnetic problems.
However, as your question was posed in September and no one has answered it yet, I´ll try to help. For fluids, people use Finite Point Methods (FPM), Smoothed Particle Hydrodynamics (SPH), Meshless Local Petrov-Galerkin (MLPG), Local Radial Point Interpolation Methods (LRPIM), etc. A good survey is presented in Katz thesis: http://aero-comlab.stanford.edu/Papers/thesis_final_katz.pdf .
Finally, I have a suggestion: if you include “Meshfree techniques” and “Meshfree methods” in the topics of this question, maybe some people from the meshfree community will see it and provide better answers.
Thank you for help, I checked the thesis by Katz and it looks very interesting. Actually, I am looking about the most efficient method for fluid-structure interaction problem with a axially moving material (plate). I don't know, which way is the best (easiest) when you couple fluid and structure and there is not many examples where this kind of coupling is implemented.
Some time ago I saw a paper from Thomas Fries where he couples a meshfree method with finite elements and solves a fluid-structure problem. I have just googled and found it: http://www.xfem.rwth-aachen.de/Project/PaperDownload/Fries_ProcF.pdf . I Think this is an efficient way to solve the problem: use meshless only where needed and standard finite elements in the rest of the problem.