Routing in Ad hoc Networks has received significant attention with a number of different routing protocols proposed in recent years. These routing protocols may be classified into three main categories: proactive, reactive and hybrid. Prior work aimed at comparing the performance of routing protocols has mainly focused on comparing reactive and proactive protocols   . In this paper, we present a simulation study of different routing protocols from all three categories. We also explore the benefits and performance of each routing category. Further, we present a discussion of future research directions for routing in Ad hoc Networks.