In addition to the Shri Rudram (Namakam and Chamakam) the following two hymns are also chanted in reverence to Lord Shiva during Shivarathri.
Bilva Stotram – A Prayer To Lord Shiva With Bilwa Leaves
Shivaashtakam – Prayer to Lord Shiva by Adi Shankararcharya
Shivaashtakam – Prayer to Lord Shiva by Adi Shankararcharya (with meaning)