All our hamsters have loved their coconut hides
And round hides. Except Raffy strangely, who ignores his and stuffs it full of paper sometimes - lol. He seems to be a bit of a gypsy actually - doesn't quite settle anywhere or relax in any hide. He sleeps in his house but it doesn't look very cosy! A vague nest and some tunnels! He spends most of his time roaming or in his wheel. Again maybe to do with his early life (or perhaps I need to tweak his set up and move the house to a different location).
So favourite items for me - because they work for hamsters usually: Coconut hide has already been mentioned.
1) Labyrinth house (multi room house)
2)Savic Rat tunnel (for syrians). Not only as part of a cage set up (I use it for the roof run usually as it's quite long for a rat tunnel) but as a way of them hopping in and out of the cage - easy to climb into - long enough they can't shoot out of the other end before you block it! It's also well made and a very nice blue colour
3) Cork logs - the large ones regardless of species. Because they're light and don't need supporting underneath, they are an interesting texture to add to enrichment, they're chewable, they make something to climb over as well as run through (also enrichment) and they can make a good ramp up to a shelf instead of a ladder - saves floor space, avoids fall risks from a height onto a ladder). Although it is quite a steep ramp up. I put them partly under a shelf or platform at an angle - so they can run up the side or run through the tunnel under the platform. And because they are a way of providing "overhead cover" at floor level.
4) The smooth coloured bendy stick bridges - because they don't have gaps. I get the ranchouse cage ones but they don't sell them on their own any more - only as a set with small platforms.
5) Any kind of ceramic hide (again it's usually round inside so they like them) as somewhere to cool off in hot weather.
6) Large terracotta plates (or smaller ones) instead of a food bowl - the hamster can just sit on it. Although with robos they usually sit inside a food bowl anyway! Also a good place to cool off in hot weather and good to put on a shelf under a water bottle that drips.
7) Similar to the terracotta plates - the square rough granite tiles that Rodipet sell - for under a water bottle - soaks up drips and helps roughen their nails when they go for a drink.
8. A platform or good sized shelf - I think this is essential - they have somewhere to go and sit under and seem to enjoy climbing up to one (somewhere to go). It's also a degree of overhead cover helping them feel more secure.
9) Hanging rat sputniks - because they give overhead cover and it's somewhere else to go. And safe, unlike cloth hammocks.
10) Might as well make it a list of 10! Snooze cubes - for out of cage time - a good hide for them to dive into when out of the cage and a good way of lifting them out of the cage (if you close the back door!) that they will walk into. But particularly good for taking them to the vets (have it inside a pet carrier) so you can lift out the snooze cube with them in it. It can stress them out being taken out and put back in a pet carrier otherwise. And it's a secure familiar place they can retreat to. I cut the tags/rings off so they don't get caught up in them.
Fuzzbutt mini Snooze Cube fleece house for your mouse,hamster,degu,glider