Help each other not re-invent the wheel - Which of these have you used?

Here is a list of different simulations and virtual labs that was curated by Arthur Lakes Library. (I love finding already curated lists!)

Some like the PheT simulations are fully open, with a CC-BY license and are already on OERCommons.org (like this collection).  

Others like Gizmos and Labster offer some free access, but full access requires a paid subscription.

So, which ones have you used? 

Which did you find most impactful?

Which did you not find helpful?