Despite what this Food & Wine article claims, the Black Velvet cocktail is not "insanely good." In fact, when Cooper and I tried it, we both kind of hated it.
But that doesn't mean Guinness won't work in some drinks.
The aforementioned F&W article mentions a Guinness and vanilla vodka concoctions, made Cuffs in Boston, called an Irish Velvet. That sounds pretty decent.
This creamy whiskey drink, the Foynes' Red Eye, also sounds good (if a little heavy).
And I think the Black and Black sounds good, too.
But realistically? Guinness is probably best just served straight.
Happy almost-St. Patrick's Day, everyone!