I haven't read all the lists in detail (I've already wasted too much money at half term on the pets) but I'll still share my favourites with Larry-Jasper.
In no particular order:
1:
Sand bath! Hamsters love their sand baths and it's a great way to keep themselves clean. Some also use it as a litter tray, but it depends how much they want to wind you up.
2. Silent Runner wheel. I don't have one, but they are supposed to be the best on the market. They are plenty of threads on here discussing them, where you can find shopping links.
3. Natural cork piece (no link). Basically, a piece of cork wood from the reptile or aquatics area of pet shops. I have found this very popular with my dwarf, who loves sleeping under it. I also scatter seeds over it, so he has to work to get them out of the little holes.
4. House with compartments. These are very popular with hams and have space for a nest, toilet area and hoard. Rodipet makes some excellent houses, but a little pricey. There is also a UK one, the Leif house, which can be purchased from Amazon or Zooplus.
5. Shelf or Lava Ledge. You can find these pretty much anywhere. I have a mini Trixie wooden shelf, which is perfect for the corner of my spare cage. Lava Ledges are quite expensive, but useful to connect upper areas of the cage together (my sand bath is attached to the bars, so this is in front).
Hope this helps
