Here are the suitable question tags for each sentence:

1. Those movies are too boring to watch, **are they**?
2. That note is very important, **isn't it**?
3. No one came late, **did they**?
4. I think she is smart, **don't you**?
5. He rarely plays football on Monday, **does he**?

Note: Remember to correct the verb form in sentence 1 to "are" instead of "is" and "plays" instead of "play" in sentence 5 to match the subject.