Adafruit Hakko Professsional Quality 20-30 AWG Wire Strippers - CSP-30-1
These are the finest wire strippers we have used, and if you have to do a lot of wiring, you will agree! They have soft rounded grips - very comfortable to use, and precision ground notches that do a perfect job every time. No more yanking or twisting to strip wires cleanly and quickly.
If you're on a budget, check out our basic wire strippers - they're not as sharp and precise but will do the job for hobbyist work.