A word of warning that only Titlis is in the Luzern area. Jungfrau and Glacier 3000 are more distant from Luzern and will take up more travel time. In particular, Luzern – Glacier 3000 is around 4 hours travel time. Also you are likely to duplicate Goldenpass route trips, as Glacier 3000 is on the GoldenPass route.
And finally a few comments about the Golden Pass route:
The Golden Pass rail route:
Current tourist branding can be confusing
The true Goldenpass is just the MOB railway Zweisimmen – Montreux.
The Luzern – Interlaken railway is actually the Brünig Pass line operated by Zentralbahn (ZB), which dubs the regular trains “Luzern – Interlaken Express’. It’s OK but not spectacular scenery
A few facts about the Montreux – Zweisimmen railway – ie the MOB (Montreux-Oberland – Bernois):
The Golden Pass is historically only Montreux – Zweisimmen, only more recent marketing branding takes the ‘Goldenpass route’ east of Zweisimmen to Interlaken and beyond to Luzern.
The Golden Pass is the touristic branding for the Montreux – Oberland Bernois (MOB) railway but after a few years of favouring ‘Goldenpass services’, the company decided it was losing its tradition and has reverted to putting the Chemin de Fer Montreux – Oberland Bernois name on publicity and train coaches.
MOB pioneered the Panoramic coach concept on Swiss trains, starting in 1976.
There are now several versions of panoramic coaches in service, but MOB keeps changing its mind how to dub each service.
It hardly matters anyway as most modern Swiss trains have large windows, even if not officially panoramic. The key element of a ‘panoramic’ coach is ‘toplight’ windows above your head but in practice very few of the major views from panoramic trains are directly above your head, so the view through the normal side part of windows is normally fine.
You will get roughly the same scenic experience from any train on the MOB and reservation is not obligatory
It is very scenic, but the MOB route is far from being the most spectacular (although any dubbing of this nature is going to subjective and personal) in Switzerland.