I've used
Fairy
ecover
Stardrops
Unger liquid
GG3
GG4
squeegee off
Never will I use fairy again! The unger liquid is very strange stuff, leaves a white smear on some types of glass! :

The GG's do make the glass gleam but don't offer enough slip at the recommended dosage.
After lots of trial & error I find the best overall solution is squeegee off with 5mm of GG3/4 added, you get good slip with a superb gleaming finnish.
