There are so many amazing places in this game. Some of my favorite yet!!!
Lumiose City is amazing with all the shops and boulevards and cafes and everything! I actually still legitimately get lost there, even though I've been playing for awhile now. So it really does feel like a big city! I love the boutique there (though it's EXPENSIVE!), and I love that you can get a job at Hotel Richissme. There's just so much to do, and I feel like I always discover new things when I go there! Plus, it's based on Paris, my favorite city, so that definitely helps things :)
Snowbelle City has amazing music (I could listen to it for hours) and another excellent boutique, plus one of my favorite gym designs. Seriously, the gym is so cool!! (pun intended)
Reflection Cave: The mirrors, the music... everything about this cave is beautiful. Even the Pokemon that appear there (Carbink and Sableye in particular) fit the atmosphere of the cave perfectly.
Dendemille Town: More wonderful music along with whirling windmills make this one of my favorite towns. I also love the name: Dendemille pronounced the proper French way sounds so pretty.
Laverre City: Love the gym and all the pretty little mushrooms strewn about :3
Entrance to Victory Road: not victory road itself, but the place right after the dude who asks to see all your badges. The animation that occurs there is absolutely epic, though I won't spoil it for anyone.
Anistar City: The sundial is one of the most beautiful things ever; this alone gets it a spot.
Route 7: Lush fields of flowers of all hues line the southern half of this route, and a glorious bubbling brook runs to the north of your path. When cycling through here, you'll be treated to a gorgeous view of all of this along with the Battle Chateau in all its glory. Truly a stunning location-- it's no wonder there are so many artists here!
...I pretty much listed half of the locations in the game, didn't I?... oops...........