My favorite general-purpose pliers are parallel-jaw pliers. They excel at crimping and grasping near the tips since they apply uniform pressure across the whole face. Since the jaw faces stay parallel, these pliers may be used in a pinch to hold or turn a small fastener without deforming its face. A small groove running down the center length of one jaw lets you use these pliers to tension cable or wire, and many models come with an effective wire cutter on the side.
I had a pair, passed down from my father, that was stolen — I despaired of replacing them until I found this robust spring-loaded pair of Shimano pliers made for fishermen. Parallel-jaw pliers are also apparently used by jewellers and tennis-racket stringers among others.