I'm surprised I haven't answered this one yet...
Ok, since I'm a cheapass (which isn't much of a surprise, being a teenager and all), I don't ever order steak...
I cook it myself.
I like to start with a sirloin or a tri-tip...
Now, whether it's on the grill or in a pan, I like to use a liberal sprinkling of McCormick 'season all' (salt, chili pepper, black pepper, celery seed, nutmeg, coriander, onion, and garlic) as the only seasoning.
If it's in a pan, I use some good virgin olive oil (it leeches a lot of the cholesterol out, without screwing with the meat's flavor). On the grill, well, it makes a good glaze on itself with its own juices when they combine with the seasonings.
Anyway, I like to cook it at a very high heat so that the outside is a nice dark brown (not black at all though...blech), and the inside is still juicy and pink--almost red at the center.
Serve with some pasta (in a parmesan and cream sauce; not cooked; just heated up by the pan after you've drained the pasta, so the cheese melts a bit), and some just-barely-crunchy-still steamed brocoli and you've got a perfect meal, as far as I'm concerned. Oh, and it isn't right unless you keep the knife in your right hand the whole time--anything else is barbaric...or else clumsy.