Meadow hay which is kind of regarded as a basic hay.
Timothy
Oat
Wheat
Barley
Botantical (no idea what that's made from!)
Alfalfa - high in calcium and tends to put weight on
Herbal hays - hays with things like chamomile in.
Mine will eat any good quality hay but like their meadow hay and the oat, wheat and barley mix that THE do best.