Jon, I don't know about most-requested, but you might peruse some of the threads that are linked in this master thread regarding song for the big day:
(sorry I tried the blickifier and it failed, but paste this in your browser and it works)

https://mudcat.org/thread.cfm?threadid=30566#394617

Personally, I might launch with "Wearing of the Green" before calling for requests, and consider whatever upbeat songs people in your area like to participate in, like Rattlin Bog or Rocky Road to Dublin or Black Velvet Band, etc., there might be more people calling for those than for the sentimental ones.