I've suffered from hand/wrist pain and numbness for years and have tried various adaptations to help address that. For example, I use mountain bike handlebars (which are slightly above seat height) and I would use the largest grips I could find to help spread pressure over a wider area. I also use long L-shaped bar-ends; on those I would place another grip then wrap the entire bar-end with cork tape. I alternate hand positions between bar-ends and grips while riding.
Recently I bought a pair of Ergon GP1 large grips, which are linked below.
I've commuted with these for a two or three months now. My commute is 6 miles one way and usually by mile 3 my wrists would start hurting. With the Ergon grips, that pain only starts now when I spend lots of time on the bar-ends.
Today I rode 43 miles and can report no pain with my hands or wrists. In fact, I did not realize the lack of pain until I returned home and reflected on my ride. This was the first long ride I can remember without hand pain.
In short, if you suffer from hand/wrist pain, I recommend you give these grips a try. Be aware of the mounting instructions because these grips should be placed at a specific angle to provide the best fit.