I know, I know - the circumstance and sauce should determine what shape you go for, but sauce aside, what shapes are special to you?
I refer linguine when it comes to fork-twirling occasions, and I have deeply fond childhood memories of rotelle (little wheels), and any really small shapes, that would normally be put in soup, served in a bowl with salt, butter and cheese (worth getting the flu just to eat that).
But I think my timeless classic has to be farfalle, the butterfly, also whimsically known as the bowtie. I love how easy it is to spear with a fork, but above all, I like how the nub in the middle is always just that tiny bit on the raw side of al dente.
Shapes aside, I follow Italians' example, and prefer Barilla and De Cecco brands. You need that hard durum to get the right nutty flavour and al dente firmness.