A very difficult question to answer as to an exact favourite, but for high resolution visual work, I tend to use eyepieces from TMB SuperMonos, Clave, UO/Baader HD orthos and Zeiss Orthos. Performance / value wise the HD Orthos are very good.
I get very good results from these but it all depends upon which scope I am using.
Wide field I like my 37mm NATO Konig and my 44mm Kaspereit. But have others I quickly grab for a casual view.
If I had to nominate a favourite? Not ultimately the best performing but much better than many modern eyepieces are two a 18mm Erfle and an 18mm Symm