No idea what 'best' would be. I bought a pair of VZ grips and, while very nicely made, I find them a little bit thin and I have medium size hands with fairly short fingers. They do definitely allow me to get a good weak hand grip when holding the gun normally with the strong hand. These are G10 grips--a material I like very much.
Also, immediately behind the trigger guard they are quite squared-off, so the middle finger of the strong hand takes a bit of a beating right at the big joint.
