I love it on sandwiches - especially Italian types like subs with salami, cappicole(sp?) ham, provolone cheese, pickled vegetables etc., etc. I've also occasionally tossed it into mixed vegetable stirfries, & have used it in certain pasta dishes as well. In fact, here's a link to one of my all-time favorite pasta dishes using Arugula, from well-known cookbook author & New York Time's food section contributor Mark Bittman:
"Farfalle with Gorgonzola, Arugula, and Cherry Tomatoes"
THE MINIMALIST; Cheesy Pasta, Redressed - New York Times