I actually like the Uncle Mikes Boot Grips that used to come on the J frames, they fit my hand perfectly and help with recoil.
I have the DeSantis clip grips on my 642 & 442 & love them. You can holster or just use the clip on your belt. An unexpected bonus for me was the fact that it sets my finger on a perfect angle to press the trigger--works for me.
I use them too and they really make carrying very easy, but if they were just a tiny bit thicker it would fill my hand better. I still recommend them though.