I too have a 2001 330XI. I just put on some General Altimax HP 225/45R17 on stock 17" rims. The tires have high ratings in all categories according to Tirerack.com's Test page.
They will give you a very comfortable ride with plenty of grip in any condition.
I paid $94 a tire. A total of $425 shipped. I received the tires 3 days after placing the order (Pennsylvania to Chicago).
The only downside I noticed was the lack of "road feel," which the old Michelin Pilot A/S' had provided. In return you get a much better ride.
The low price and versatility of this tire are what give it value.
My 2 cents
Link: (now $107/tire)
Last edited by CLP-WGH; 02-01-2013 at 07:36 PM.