For MAs: I always have a good time with Lillian at AT/PS, and Evelynn at Alpha. (base rate sessions with both). I've visited Alison once, but I'm sure you'll always get a great experience everytime. Abby was my go to for RMT style session, although last time she got a bit too distracted with the cellphone for my taste.
SPs: couple of times with Jessie Celeste were good, not a clock watcher. She updated her rates though, so she's not in the 300 or less bracket anymore.
Alma has been fun as well, but I haven't seen her recently, so I'm not sure if the donation is still the same.
This thread is a good idea. Hopefully people will share some more.