First-party:
Nintendo Land
Super Mario 3D World
New Super Mario Bros U
Mario Kart 8
Pikmin 3 (freebie I chose with MK8)
(promo version, just paid for the pedometer part)
Third-party:
Rayman Legends
Call of Duty: Ghost
Assassin's Creed III
Sonic Lost World
Toki Tori/Toki Tori 2+ (counting this as one)
If it weren't for the MK8 freebie deal, it would be 50% each way (and I would have bought MK8 without the deal). In terms of games I've paid for, 3rd party comes out slightly ahead, at least by number, it's a close race by total spent.
EDIT: Not voting at this point in time, because the balance is likely to shift over the next few months. Sonic Boom goes into the Third Party column, while Hyrule Warriors, Bayonetta 2 (about 90% sure I'll get it), and Smash Bros are all in the First Party column. Watch_Dogs was on my list of planned titles, but whereas I was almost certainly going to buy it prior to its extraordinary delay, I'm now on the fence regarding it. Also in the uncertain category is Captain Toad (but that's looking to be a January 2015 release in Australia).