Confession - I totally love Parmesan. I don’t have a ton of cheese experience but I love the nuttiness and how strong it is. I’m not a large fan of the center-back of the tongue taste of Bleu and Brie isn’t exciting for me to eat as a small snack, but I love love some Parmesan. However, I want to expand my taste and find something stronger and better. Should I just get a really really good Parmesan and threaten with crucifixion those who dare to grate it up into powder over pizza? Or is there a different cheese that’s like it but way better? I’ve become a fan of really old Gouda too (which is nutty and similar) but I’m still in the market for opinions.
Aged English cheddar has a nutty quality. Montgomery’s clothbound cheddar is excellent. This type of cheddar is different from American cheddars: it’s earthier, nuttier and more crumbly.
I was going to suggest aged Gouda as well. Anything in the 5-7 year range is pretty nutty and what I might describe as having raisin-like fruit flavors. One of my favorite cheeses. (On preview: But I see the OP has already mentioned it.)
I also agree with pecorino and provolone. Proper Roman Pecorino is excellent for snacking, stronger in flavour than Parmigiano (I’m never going to call it “Parmesan”, for Pete’s sake), much stronger than cheddars.
Asiago, if you’re serious about it. Aged Asiago, if you’re really serious about it. Good Pecorino romano has this quality, but from 1½–2 times as much as Parmesan. In Italy I encountered an extra-greasy variety of Pecorino full of whole peppercorns, which was served to me as a slab on a plate for dessert(!). As for Parmesan grated onto pizza, of course I do. It forms the perfect browned crispy top surface. Nothing else browns as perfectly as freshly-grated Parmesan. If you like to snack on nutty Parmesan, you absolutely must try frico—lacy, crispy pan-fried wafers made of Parmesan grated into long elegant strands. The essence of crispy-browned Parmesan toppings for other dishes, isolated into a delicate creation all its own.