Vibration through steering wheel

Well I've had this problem for a while now. Car has 82,xxx on it at the moment. I've had the car aligned 3 times by 2 different people, tires rotated and balanced 4 times by 3 different people and its still there. Some done for regular maintainence, other to hunt the problem down. Its worst around 50-65 MPH. I've actually had passengers ask why my steering wheel shakes so badly so that gives you a clue as to how bad it is. Its worst in straight driving but not quite as bad as when I make a turn (either way).

Any ideas on what to check? This makes driving less fun.:(

Thanks in advance.

is it just when you first start out, or do it continue the whole time you are driving?

Continous. Doesnt matter if its been sitting for 6 days or 6 minutes. I can get in it cold and it shakes at 50-65 really bad or I can drive it 30 or 40 minutes and the vibration is there and then I get back in it after a few minutes and its still there.

Any clue as to what to check?

Check for broken belts in your front tires, check your rotors. Try to get a balance done that incorporates the whole wheel, tire, rotor assembly.

You have a tire problem. To verify it, switch the front tires to the back. The vibration should then be most noticeable in the seat of your pants. If this happens then you know it's a tire problem. Then switch just one of the rear tires back to the front and see where the vibration is felt the most, steering wheel or seat of your pants. If the steering wheel vibrates then the tire you just rotated to the front is the problem. If the vibration stays in the seat of your pants then the tire you didn't move to the front is the bad tire. I suspect it will have a broken or shifted belt. Get it warrantied if possible or buy another tire to replace it and your problem should be gone.

Thanks for the input guys. I'll try to alignment deal today and the rotation.
Thanks again

Alignment is probably a waste of money if you are chasing down a vibration. Rotate wheels to track it. Align only if you are showing unusual wear patterns or for competition purposes.