We used Happy Limo for our trip last week. $182 r/t, if I remember correctly(and that didn't include tip).
It was more expensive than renting a car, but we just didn't want the hassle. Plus, we'd gotten a great deal on our flight, so we didn't mind the extra cost.
Picked a towncar for our service. Drivers were right where they were supposed to be at the right time. Both were very friendly, professional, courteous, and got us there in about 40 minutes each time(might be off on that, I wasn't paying close attention).
I would definitely go that route again.