I first tried the plastic comb that came free with the anti-lice hair product ("Resultz" brand). Although the Resultz product seems to have worked well, the plastic comb was pretty flimsy and several teeth broke off while combing my daughter's hair.
I then bought a double-sided metal comb ("Nix" brand). This worked better, but not great. The de-tangler side was good but the de-licing side missed quite a few nits. Even when I could see the nit, I sometimes had to make multiple passes to actually grab it. Also, some of the metal teeth fell out, although I was able to reinsert them into the plastic holes.
Today I received the NitFree Terminator that I ordered from uRush on Amazon. Definitely a much better designed product. The "microgrooved teeth" actually work very well. Unlike the other two combs that I tried, I would definitely recommend this one.