Displaying LEGO is always tricky, because dust is very annoying. It's something I constantly worry about with my displays on my shelf, because it is so very annoying to remove. It just looks ugly on display.
While my plan is to use model car cases for things like the DeLorean and Curiosity Rover, and some big clear cases for minifigs to grandstand on, I would rather have a few figs stand out. I have some cases, but that's still not good enough. Things can be touched easily, and I am always rotating out which minifigs get displayed.
So I found these little things that came with Pokemon toys inside them. They're relatively cheap (or cheap enough) and look great.
The pricey minifigs in the upper pictures deserve a bit of separation from the rest of my collection. The chrome Star Wars figs shouldn't ever be touched with bare fingers, and the two Comic Con figures have a nice sentimental value. (Their high monetary value also garners them some extra respect.) The TRU Force Friday brick could be moved elsewhere more visible, but it's big and bulky and doesn't quite deserve to be unintruded. It's a nice piece of history though.
The Avengers in the lower pictures were a gift for a friend. She had a few of the "main six" from the movies, but needed a few more characters to complete her collection. I put them in the display case on some bases adhered with sticky tack, allowing for the mirrors to really show them off.
I have one more case which needs filled. I can fit 5 figures without overshadowing anyone, so it's just a matter of who. Something special, something cool, and something I won't want to take out to use in a vignette. I've got a lot of figs to choose from, so I'll make it count.