check out Car and Driver's most recent comparison test of summer tires, on their website. Tirerak,com also has good surveys where buyers have rated tires, by attribute.
I have a 328i with sport package and have Continental Extreme Contact DW. Decent traction in both dry and wet, good treadwear rating.
AA Stage 2 - M3 control Arms FR - BMW PS2 - Dinan springs - APEX EC-7 - H&R front swaybar - Whiteline subframe inserts