My favorites have remained fairly steady the last few years. Here's a blog entry I wrote about it a couple years ago, and these favorites continue to catch a lot of crappies for me.
http://fishndave.blogspot.com/2010/10/crappie-fly-patterns.html

If I had to pick just two favorites...they would be microjigs (all-chartreuse or gold/natural...Springbrook Wunder-style (bright red thread)) under an indicator during daylight hours, and #8 unweighted yellow boa yarn leeches after dark.