Well, obviously all my mons were (Or eventually became) Ice-type. Until after Shelly I had four Pokemon: Snorunt (My lone Starter, didn't go for a full early-team), Seel/Dewgong, Vanillite and Sneasel. After that I was able to pick up Cubchoo/Beartic and Smoochum/Jynx. This was the part where I had probably the most issues with, between Victoria, Fern right before Aya and ESPECIALLY Kiki...yeesh, I still have PTSD nightmares when I fight her now. After that, right before Radomus I swapped out Dewgong for Glaceon (Obviously), then Jynx for Amaura/Aurorus before Luna. So my team right before Agate was Mamoswine/Weavile (Evolved not long before Radomus)/Vanilluxe/Beartic/Glaceon/Aurorus.
Post-Agate I got a number of extra options, though only one of them really stuck: Walrein replaced Vanilluxe, though that was only after Samson. I swapped Jynx back in for Samson, replacing Vanilluxe, before Walrein took her place permanently. After that...yeah, I swapped in Dewgong back in in place of Beartic before replacing both with Froslass for Blake (As well as Mamoswine for Rotom-Frost...in fact take Blake's Team, replace Jynx with Glaceon and you have my team for Blake + Terra). After that I went back to Mamoswine/Glaceon/Walrein/Aurorus/Weavile, as well as training up Lapras for the Mansion Gauntlet. So yeah, my final team as of the end of E15 is Mamoswine/Glaceon/Walrein/Aurorus/Weavile/Lapras, and I can assure you all six of them are fully able to handle anything that comes our way.