Dude that's a really big question there are so many different types of 'steak' at the end of the day it's a very vague term. I am talking about a general Ribeye beef steak which here in New Zealand is a standard thing on most menu's. It's mostly a matter of personal preference if it's cooked well (as in good not well done) it should be juicy and nice either way but it's more a matter if you liked the cooked flavour or the raw flavour. If you like the more raw flavour you'd go for a blue-rare steak it can be slightly chewy which can put people off cause you're effectivly chewing on warmed raw meat with a cooked outside which kills off most of the bugs and stuff. Once you get towards med-rare - medium it will have the most warm juicyness but still have a bit of red meat in the middle but it wont linger as much. Well done if cooked well should be a bit less juicy but will be brown all the way though with no uncooked meat. In all cases the idea is to cook the full outside and get the inside warm it's just more a matter of how much brown vs red meat you want and what your preference is for flavour.

Sorry for the ramble I'm a little drunk.