Rare....I like a thick filet (12 oz) seared on both sides for about a minute and a half. That leaves the outside crusty, but the inside extremely rare. As far as seasoning, I like to dry-rub the filets with a mixture of garlic powder, black pepper, and cayenne pepper at least 4 hours before going to the grill.
You can tell a good piece of meat by the "quality of the fat on it." I love fat on my steak. I know it's sooo bad, but say "What the hey"... The fat on it has to melt in your mouth like expolding butter! If it is chewy and hard all the way through, usually that peice of meat is going to pale in comparison to what mentioned above. You guys know.....