Bendy bridges are also good. Here are some of my favourite hamster toys for cage enrichment.
Hyacinth tunnel - chewable and they like the holes
https://www.amazon.co.uk/Rosewood-Bo...2130721&sr=8-2
Rat sputnik for hanging from the roof (also provides something to sit under so they feel less exposed), It works best hung next to a shelf so they can get in easily and with some substrate inside.
https://www.amazon.co.uk/Savic-Ferre...8-2&th=1&psc=1
This cork log from rodipet. It's large for a tunnel but also makes something to climb over that's an interesting texture, and if next to a shelf can be used as a ramp instead of a ladder.
https://www.rodipet.co.uk/accessorie...-diameter.html
Trio of balls. I only use the hyacinth one in the cage - you can stick pumpkin seeds under the folds and they have fun getting the seeds out. The sisal one I unravel and use for sisal string for tying or hanging things to the cage (it's safe to chew which normal string isn't and chains are dangerous as they can get a foot caught). The wicker one I don't use as think it's a bit sharp.
https://www.amazon.co.uk/Rosewood-Bo...2131036&sr=8-1
Also have a look at Erin's Hamsters 10 toilet roll toys video.
https://www.youtube.com/watch?v=NuPeyD6w-CI