I do gunpla building, and the one thing you see most builders, regardless of level, immediately want to go for, is a pair of good single-bladed nippers. Usually the holy grail are the God Hand japanese brand nippers, as they perform a very clean and close cut to remove the plastic nubs off the parts, but other less expensive options exist. Sure, there are many different ways to deal with the plastic nubs that stay when you cut off a part from the runner, but the one tool almost everyone goes for, are those nippers. Usually, to the point of keeping two pairs, one to clip parts off the runner, and one just to cut off the nubs.