I could rattle off many things things that go well together. Things like chips and salsa, chocolate and peanut butter, or Saturday mornings and sleeping in late. (I haven't experienced that last one for a while, of course, but I remember it with unparalleled fondness.)
Of course, there are also combinations that don't mesh nicely. For example, today I heard my six-year-old talking with my three-year-old and juxtaposing these two phrases:
let's race and down the stairs.