Two mainly. The EF 180MM f/3.5L Macro is good for larger insects like butterflies and dragonflies. It works as a portrait lens too.
Then for deep macro, I use the MP-E 65mm f/2.8 1-5x Macro. It gets in deep, but can't take pictures of anything bigger than 3.5cm (2.4 on crop)
Then sometimes I'll use the EF 300mm f/2.8L with the 2x TC II to get some sort of macro shots. Decent for far away objects, but also some closeups when needed.