I have two plants in one pot and have no idea what either are. They both look 'succulenty'.

Both are kalanchoes. The taller one with some spots on the leaf, looks like a Kalanchoe marmorata.
The other more prolific one that has lots of babies at the edge of the leaves looks like Kalanchoe daigremontiana nicknamed Mother of Thousands.

First of all, Andy...I love the title of your thread and second...I agree with Mother of Thousands. "They" say they (MoT) or hard to kill/get rid of, but alas not for me. Actually wish I had one still.

For comparison of the taller plant: Spotted Kalanchoe (Kalanchoe marmorata) and as tarev suggested, the shorter one may be Mother of Thousands (Kalanchoe daigremontiana)

I think the shorter one may be K. laetivirens.

A lot of the pics in the DB entry here for K. diagremontiana also look like K. laetivirens. K. diagremontiana looks just like K. x houghtonii, but there's a little cup shape where leaf meets petiole, the edge of the leaf folds up right at that junction. Brown spots on the leaf backs. This Wiki pic shows that well:
http://upload.wikimedia.org/wi...

The Kals that make leaf-edge babies (the mother-of ones) have been moved to Bryophyllum.