I crave the sharpest cheese

Sorry if this is not the right place for this type of question, but I thought I'd atleast try.

I love the feeling and taste of really sharp cheeses, like an aged Parmesan. When you put it in your mouth you instantly start salivating, and it's so tangy and sharp and crumbly and salty it's almost painful to eat. God I live for that feeling.

But what is the sharpest cheese? The kind of cheese that's almost difficult to eat due to it's sharpness. I've tried aged Parmesan, and I've heard good things about really aged Cheddar (+3 years maturing) but I can't find that anywhere near me. Are there any other really tangy and sharp cheeses that I could try out?