Stock SPI parts for robots

I’m trying to compile a list of parts that SPI offers that teams have found useful for construction of their robots- mostly in drive systems, obviously.

If you or your team have used SPI and integrated parts with very little effort into your robot could I trouble you for either a photo and a description or a part and description?

I’m not a MechEng by training so I’m very limited here.

Thanks in advance!

Jason