I thought I would comment on some of the "passalong plants" that I have. These are plants given to me by others. Generally, I got plants that were prolific in the giver's garden, and so they are equally prolific in my garden.
The number one plant on my list is not prolific, it is a big, awkward, house plant. It is a "night blooming cereus", more specifically Epiphyllum oxypetalum. I got mine from Dad, who got his start from Louisa Valentine, who was an immigrant from Czechoslovakia. (Though I doubt the plant came from there!)
I've never seen one for sale at the local garden center or discount store, so I assume that the best way to get one is to get a start from someone who has one. Though, with the internet, I'm sure you could find one quickly enough. The name 'night blooming cereus" comes from the fact that the flower opens up and then fades away, all in one night. (Yes, like the flower in the Dennis the Menace movie.)
I waited 13 years before mine bloomed, then it bloomed two years in a row. The bloom is large, maybe 6 inches across, white and very fragrant. It is almost too fragrant for the sunroom where I have mine. The scent was almost overpowering inside.
After it bloomed twice, I had to re-pot it because it was all top heavy and the pot kept toppling over. It hasn't bloomed since. I believe it likes to be fairly pot-bound before it blooms. Mine is now in a 20 inch pot on the floor, with a five foot trellis to support it, so it may take some time before it is pot bound again and blooms again. It's a big mess of a plant but it's special to me, so I will continue to devote a large part of the sunroom to it.