The most common Latin root is co. This root appears in more words than any other. Literally hundreds of words. It has other forms: con, com, and col; they all mean the same thing. Together. Or, more specifically, they mean with, together, or joined.
Kind of nice if you ask me. The most common nugget of meaning, or morpheme, means together. As in community, connect, coordinate, cohabitate, concentrate, converse, complete.
By comparison, the Latin root fract, which means break, and is found in words like fragment and fracture, is not very common (there's that "com" root again) at all.
Of course, the Latin stem im occurs in a lot of words too. It means not, and it also takes the form of il or in. It is in hundreds of words. Illegal, illicit, illegitimate, immoral, indignant, inscrutable, impossible, improbable, inconsistent, inedible, incredible, and indelible, to name a few. The list is nearly infinite. But im, though common, doesn't really have any meaning of its own. Its a negative. It negates. It doesn't have substance of its own, so its frequency says less about the human condition and more about the convenience of language. It's a convenience prefix, that can easily be tacked on to the front of a word to create an opposite.