Jesse I love this topic, thank you for starting it.
Hmmm, I'll have to think about pairings. I haven't been very good at it in the past, but thinking more along those lines lately.
Here is 'Abba' and Sedum 'Ruby Mantle'. This combination was a total accident.
Delosperma 'Blut' and S. 'Black'
D. 'Garnet' and S. 'Vanille'
'Green Caressa', 'Pink Red Tina' and 'Hordubal'. Each is so different that if they grow into each other it is easy to tell them apart.
To be honest, I can give a favorite, because it can change from one day to the next. Depending on the season and lighting. And I also love to grow other types of plants with the semps.