Delay sensitive applications, such as voice over IP and network games, often sacrifice throughput for lower delay to obtain better quality. Unfortunately, the Internet does not allow an application to choose the amount of delay or throughput it receives and instead packets from all applications receive the same best-effort service. This paper presents a new QoS mechanism called the traffic sensitive quality of service controller (TSQ) that provides better delay performance for delay sensitive applications and higher throughput for throughput sensitive applications. Also contributed are quality metrics for some typical Internet applications that can be used by an application to adapt its delay hints and evaluate QoS based on current Internet traffic conditions. Experiments suggest TSQ's benefits to performance along with retention of the current best-effort Internet environment without complicated traffic monitoring or policing.