The old model Snap On 47ACP are probably the best slip joint pliers ever made. They are everything you always wanted a slip joint plier to be and never were. The jaws are super stiff with beautifully machined teeth that meet perfectly. You cannot get the jaws to dislocate when twisting. To move to the larger opening notch, you must open the handles a full 90 degrees. They will never just slip between opening sizes.
The shape of the jaws is what sold me. They are wide, but come to a pretty fine point, almost like duck bills, which are generally my favorite pliers. You can reach into spaces and grab just a tiny tip of something, like a cotter pin, that other pliers would struggle to remove.
Snap On isn't still making these. They are black, btw. The new model 47ACP are the "talon grip". They are larger and clumsier in my opinion. The old 47ACP is like a cross between a duck bill and linesman pliers. In many ways they are better than both.
I really appreciate the fact that Snap On took a basic tool and made it better just by giving the machinings the respect they deserve.
You can find these on eBay for around 20quid. Buy a set before they disappear.