Household Items that make great toys:

Toilet roll tubes stuffed with hay. (Cut lengthwise to prevent baby rabbits getting stuck).
Tunnels.
Paper bags, again can be stuffed with hay or just on their own. NEVER plastic bags though.
Soft toys with pet safe bedding inside or even hay! Ours love them.
Empty cardboard boxes. (Not laminated) These are also GREAT to nibble on which helps to naturally trim their teeth.
Cosys/cuddle cups. (Available to buy).
Always provide them with plenty of wooden toys.
Towels, hang them from cage bars or even just lay them in the cage. They make great hideys.

Hay Racks And Hideys

Cereal boxes stuffed with hay and holes cut out.
Stuffed animals with hay in them - A big hit, can be used as a toy they sleep with as well as a hay rack. Portable too!
Old peg baskets used for hay or grass - Ok as a temp solution. Was very messy.
Kitchen roll tubes - One of my favourites as they're completly edible!
Toilet roll tubes - One of my favourites as they're totally edible!
Boxes - Great as they make hidy holes too! Also completly edible.
Hay balls - Gives rabbits a nice little challenge.
Plastic tubs (great for your rabbit to toss about).

Commercial toys

Cat balls, rabbits love to push them around. Try the ones with bells in.
Wooden hidey holes. Rabbits love to chew on them which help to trim their teeth. Buy the biggest you can find as your rabbits will grow into them.
Wooden hanging bird toys.