I had my nephew, a young man serving right now in Afghanistan, along for a ride on the back of my FJR a few weeks ago. He's pickin up a GSXR 600 when he gets back, his first bike. We were miked up, and so I took advantage of the opportunity to share with him some ways of thinking about lane position.
I told him that when I am riding along a straight, two-lane road, I pick my lane position according to where I think the hazard would come from. So I ride close to the center line when no cars are coming, because the hazard is animals, cars, or kids jumping out from the sides. When a car approaches me on a straight road, I move to the right because now the tangible hazard is the cager coming toward me who might cross over (CAJW just told me yesterday about a couple killed coming out of Yosemite when an 18-yr-old girl in a pickup crossed over and struck them head on).
Entering a turn, staying right makes a lot of sense in the event a motorcycle or other vehicle coming the other way crosses over. But there may also be a bicyclist or slide right around the corner. And if you're being fairly aggressive, going into a right-hander too far to the right leaves you very little room for error if the radius decreases (as CAJW pointed out to me yesterday, something I hadn't thought of).
On freeways, it's a whole different ball game, but same principle. I like the no. 1 fast lane because it gives me an out to the left. Moreover, I like to cruise in the left track of the left lane, particularly when the no. 2 lane to my right is moving slower, and always when I'm in an HOV lane and the next lane over is practically stopped, but I'm going 65! A very scary situation.
When on the freeway in traffic going up a center lane between cars going slower, I tend to open up my vision and weave a little like a boxer, moving slightly in my lane toward the pockets between the cars to stay "staggared," while anticipating that a car could jump at me from either direction.
When riding a few years ago behind my brother-in-law who was on a Harley tractor--some big-*** thing with wheel-barrow handlebars--I noticed he planted himself on a two-lane twisty in the left wheel track and just stayed there the whole time. I think his idea of being "experienced" and "skilled" was riding like you were on railroad tracks. Crazy!
That's the [really
] long answer. Short answer is, there are many right places to be, depending on your risk tolerance and the situation.