-Joltenne: Relaxng by the beach, with some sunbathing or some swimming, and definitely a nice BBQ with all her friends.
-Kaito: A serene treck through the jungle, some meditation or a cozy place to nap, as well as somewhere to train his swordmanship.
-Sabi: family vacation where she can just kick back and not worry about work
-Andreas: Nice outdoor sports, tracking or a beach with some pretty babes!
-Icebella: Somewhere secluded and ampering, away from public eyes

for penelope, it would be.. almost anywhere in kalos! especially the larger cities, such as lumiose or shalour city. she's always wanted to travel there and sightsee-- in lumiose, she'd want to get a taste of those chic boutiques. she'd either want to go alone or with someone special!

Balei would love to travel to a big city.
She already lives in a region chock full of beautiful beaches and other scenic views, Unova is her no. 1 place of interest

For Grim it would be anywhere peaceful, in all honesty if he didn't had so much emotional baggage related to Sinnoh, he would probably vacation there. Anyways, what would he do? Literally nothing, just relax for once. He would most likely take Kazi with him, or go by himself if she can't make it

Labi would love to go to Lumiose and go to every boutique and take several selfies around the place.