Strut mount problem??

My car is a 2000 Sunfire GT. I have been having a bit of a front end problem since about July last year. It used to clunk when I turn and when I let go of the wheel after turning, it will roll back to a point about 1/8th around and it will stop and not come all the way around. It no longer clunks very often, but the wheel still doesn't return to centre properly. Lately I have been having other problem with it too like the turning is not as responsive, especially at highway speeds. The steering feels looser than it should be. Now what I am finding really weird about this is that my alignment never seems to be consistent. Some days it will pull to the right, others to the left, and sometimes not at all.

Any help diagnosing this problem would be greatly appreciated. I am hoping to fix this myself and soon. Thanks again.

So I changed the drivers side strut mount and the problem persists... Does anyone have any suggestion for what else it could be?

Just a guess;
Power steering pump, or rack and pinion setup.

Thanks for the help. It would seem that my problem was in both the steering gear AND the strut mounts. I replaced both strut mounts today and that cured some of my problem but it would seem my steering gear is messed up too.

EDIT: I took it to the mechanics today and they said that the steering gears/rack are fine and that my only problem right now is the alignment, I was so happy to hear that