My Beloved Wiha strippers have been EOL'd by the manufacturer, try These ones from Knipex.
For most people, most of the time, These ratcheting pliers from Adafruit are good. Beware imitations, not all tools carrying that part # are identical.
None of them are spectacular or anything. These Cheapies from BangGood are fine.
Start with square pin headers in a few sizes. They're easy, forgiving, and cover a lot of bases.
The SL series stuff has both male and female crimp terminals, which can save your bacon in certain circumstances.
www.FerrulesDirect.com - where else? They also have other goodies. Look around. Notice that there are a couple different standards for size/color pairings, buy out of the same standard each time or risk confusion, it's hard to tell the small ones apart by eye.