“Roe to perdition” is the caviar one, and it’s fantastic as well (#20 for me). Niles trying weed was #1 for me, “high holidays”. For me, #2 and #3 were “the doctor is out” (Frasier getting involved with Patrick Stewart) and “out with dad” (where Martin and Frasier go to the opera). The misunderstandings are what does it for me!
Edit: But I'd honestly say that my whole Top 50 or so is great episodes, there's not a big gap between the top and any of them. It was hard ranking them all.
Also, my list is at: https://tvsort.com/show/3452/matrix_01hjtxz2e1ewkrh44ja3mz0s...