3 hours for Air on the 2nd weekend after it opened. Apart from that, I don't queue for more than 90 minutes. No matter how good a coaster is, I'd prefer to have four rides on a slightly inferior one than spend all that time queueing.
For new rides, I now take days off work during the super off-peak, during a week when it's wet and rainy so I basically have the park to myself
I don't know about coasters but the longest Queue I've ever seen for a flat ride was Soarin' at Disney's Epcot in Florida. The queue peaked at 3 hours and was usually around 2-2 and a half hours for most of the day! And that was only last year...
Thank godness I had a fast pass even though the wait was close to an hour!