In my opinion, you should get either Mario Kart 8 or Kid Icarus Uprising. Kirby Triple Deluxe is a fantastic game, but if you're looking for something that will last you a while, it's not the game for you. I found it to be pretty short. I've never played Bayonetta 1 + 2 or Fantasy Life (though i'm planning on getting Fantasy Life soon), but Mario Kart 8 and Kid Icarus Uprising are great games.
I bought MK8 a month after its launch and have still been playing it pretty often, and I still have a ton of fun with it. The online community is still pretty active, and I still enjoy playing the grand prixes again and again. If you have amiibos, they definitely extend the fun of the game! I have a Captain Falcon, Samus, Fox, Yoshi, and Donkey Kong amiibo (My friend also came over with his Kirby amiibo and gave me Kirby's suit), and I love the Mii racing suits they gave me! The suits are only getting better with the upcoming update on April 23rd (For me, i'll be getting Mega Man, Bowser, and Rosalina's suits on that day, so i'm excited.)! However, if you buy Mario Kart 8, you NEED to get the DLC. It adds SO much more to the game! DLC Pack 1 is amazing (I especially love the Yoshi Cup), and i'm so excited for DLC Pack 2 (Animal Crossing track? Cheese Land? Ribbon Road? A new F-Zero course? How can you not be excited for those!)! Plus, if you buy both the DLC packs, you get the different colored Yoshis and Shy Guys, and personally, I love playing with them! Mario Kart 8 does have its flaws, though. The character roster isn't all that great (There are too many babies, the koopalings are all really similar, and why is there Pink Gold Peach!?), and the battle mode is absolutely TERRIBLE because it doesn't have any courses that are actually designed for battle mode (though Yoshi's Valley sort of works as a battle mode track).
As for Kid Icarus, I haven't played it in a while, but I thought it was an outstanding game. The story mode was really fun (though some parts of the story could've been better, imo), and it was great to compete against others in the online multiplayer. I'm not sure how active the online community is now, though. From what I remember, the bulk of the offline single-player has you replaying chapters of the story mode, especially after you beat the story mode (though, trust me, they're very replayable). You could forge and collect different weapons throughout the game, and you can use them in the story mode and online multiplayer mode. There are also challenges (similar to Smash Bros) that you can try to accomplish that each have you do something different. For example, I remember one of them was to beat the first chapter on intensity level 9.0 in 2 or 3 minutes. There are many other extras as well (like the idols, which are basically like Smash Bros trophies but in Kid Icarus).
Overall, in my opinion, i'd go for Mario Kart 8, especially with the new DLC, 200cc, and Mii racing suits. If you're more into action/adventure games, though, Kid Icarus will probably be for you. However, keep in mind that a lot of each game has you replaying it (Mario Kart more so than Kid Icarus but each has you replay it a lot).