I usually either save in front of PC's at the Pokemon Center, or in Driftveil. That place's music is LEGIT.
But a saving depot would be an awesome addition. kind of superfluous though since you can already save anywhere lol
I often visit Accumula town and Opelucid city. I like the music in both locations and one is near my level 40-56 level up spot. You could consider Opelucid my first home while I have a summer home in Accumula town.
I tend to save wherever. Lately it has either been on Route 3 (egg collecting) or the Skyarrow Bridge (egg hatching). I do tend to shine up my badges every few days before I save. I only tend to remember them as I am about to save, which makes me have to shine them before I save.
If I'm just going through victory road or something ill save right there.but otherwise,ill fly to driftveil and save facing forward in front of the PC,so I can start my game with driftveils awesome music.