I was looking through tirerack.com and from what I've seen, the best tire on there were the Pirelli PZero Nero's. At 225/50-16, comes at $100/tire but also come with high ratings. My old Pirelli's lasted ~40,000 miles (Mercedes 190E) with spirited driving. Now, on my 328i, I'm looking into a newer more advanced set. There are no Discount Tire outlets in my area, so STS charging $37/tire installed is my next best bet.
Check out the Pirelli's stats:
Click Here
I saw most others and wasn't really impressed. The dealer told me to only purchase Continental tires stating that Pirelli's were the "WORST TIRE FOR ANY BMW." These Pzero Nero's got alot of good reviews. They'll be my next set, soon I hope. My bald tires may not last the rest of the week.
Dough