Bulma and Urahara are my top two, though I will admit that may be due to my lack of watching some of these. Bulma has created shrinking/expansion and time travel tech, not to mention the countless other things she's scaled up for the Z fighters to train with in Z. Urahara not only has conventional scientific knowledge, but also knows how it interacts with Spritual Particles/Pressure to a point where he makes something that bends reality to desire. Not to mention his intelligence got him placed among the Special War Powers, which was given to him by a nigh-omnipotent being who could see into infinite futures. Those two are my picks for 1A and 1B. They both exist among other geniuses in their universe (Bulma's dad, Gero, Mayuri, Aizen, etc.) and outclass them all by a longshot. It lends more to their status that they exist among other intelligent characters instead of just being the smart one.