Two "alternative" cuts for the beef connoisseur.
Skirt steak.
http://www.asadoargentina.com/asaa-images/entranraw.jpg
Hanger steak (aka hanging tenderloin or onglet).
http://www.lobels.com/store/main/item.asp?item=25
Both are incredibly flavorful, take marinades well, and are buttery tender if good quality and cooked right. They must be grilled quickly over very high heat and not allowed to overcook or they turn to rubber. You should butterfly the hanger steak and flatten it out a bit.