5s, 9s the most. Sometimes 6s.
I find that I can talk to 5s in more 'depth', and can also explore the darker side a bit more, though that may seem superficial. 9 is also patient, receptive and can be 'deep' in communication partly because they can adapt to other. The communication feels more deep and not as 'light' as with 7. I also like 8s, 2s and 3s at times. 1s, rarely. 4s, sometimes but I find they can be difficult as well.