To be honest, it all depends on the steak, but I'm more of a medium-rare kind of guy. Tenderloin (filet mignon), for example, is better if it's rare. But, a nice cut of ribeye is better if it's medium-rare. Obviously, that's just my opinion, but my opinion is awesome.
I'm not real big on prime rib or roast beef cuts because they are typically prepared much to rare for my liking. Trouble is, when you cook them to medium well they always end up too dry.
medium rare, it's gotta have some pink and when you press down on it, juices should come out and I love to load my steak with spices and also marinate it... Jesus I am drooling all over my keyboard right now