They can be really hit and miss, some my dog figured out in seconds, others took longer. A lot of the moving shapes type games she wasn't bothered with once she solved it.
The commercial things she really likes
Trixie turn around
Starmark Bob a lot
Kong wobbler
Snuffle mat
9 carrot plush mat
Homemade
Muffin tin game - put a ball in each hole with treats under each one.
Ball pit ball box, 6 inch deep large plastic storage box with a set of kids ball pit balls in. Scatter treats inside. They are flimsy and some get crushed but largely ok.
Scrunched up paper box, 12 inch deep plastic crate filled with scrunched up newspaper/tissue paper and treats scattered inside.
Rolled up knotted towel with treats in
The most popular thing was a baby toy from Aldi, it was a fabric tree trunk with 3 holes in and 3 small squeaky birds inside. I think they also did an apple with squeaky caterpillars. I fill it with more small toys and pop a few small treats in. She spends ages removing all the toys.
We also have a small kids basketball hoop placed low enough for her to reach and that gets played with a lot.
She also enjoys a sniff trail. I put her in the garden while I leave a trail of small treats around the house. Some easy to find, some harder. You can hear her nose in overdrive while she looks.
I joined a canine enrichment group on Facebook for a while and got some great ideas there.