It depends on the age we are talking, but I recall Hardy Boys, Hardy Boys Casefiles, Classics like Robinson Crusoe, White Fang, (at first it was the "comic book" version of those before I was able to step up to the actual novel), but my favorite ones were the "101 Weird Science Facts" and the like. (101 Weird Animals, 101 Amazing Survivals Stories, etc...)
Thinking back, it isn't any surprise my mind is almost a Wikipedia full of useless knowledge.