In every such list I've read, one rule that gets passed around is not a rule: "A preposition is a word not to end a sentence with."
Although it's not a rule of grammar and appears in no reputable textbook, it's still a good rule. The reason isn't because it's a preposition but because prepositions are weak words. The same rule applies to most adverbs. Consider the difference between these two sentences. (1) He knocked over the box. (2) He knocked the box over. Both make sense, but box is stronger than over.
Let's go back to that supposed rule: A preposition is a word not to end a sentence with. What is the most important word in that sentence? Obviously, it's not with. The writer, of course, has to make that determination, but I opt for preposition, so I would say: Don't end your sentence with a preposition. Or I could write: A preposition is not a good word with which to end a sentence. That places emphasis on sentence. If I chose the word end for emphasis, I would have to say, somewhat awkwardly: A preposition is not the word to use for the sentence to end.
Don't avoid ending sentences with prepositions, not because of any rule.
Avoid ending sentences with prepositions because you want strong endings.