Nintendo has three significant releases over November and December; Hyrule Warriors: Age of Imprisonment, Kirby Air Riders, and Metroid Prime 4.

Of these, which do you expect will sell the most lifetime, and what's your reasoning for why you think so?

That's a toughie. Metroid is hyped, but almost exclusively for core gamers or Metroid fans. Hyrule Warriors is taking a massive IP like Zelda but using something more obscure like Dynasty Warriors. Hyrule Warriors to date as a whole has sold about 6 million so far. But Age of Calamity did sell about 4 million units.
Kirby has the broadest appeal. Kirby is a popular character, and his brand of cartoon racing is different enough from Mario Kart to be worth it to people.
Kirby wins. I think it's the game most likely to sell 5 million copies lifetime even if it's an uphill battle.

It’s close between Kirby and Metroid for me. A hotly anticipated spin-off from one of Nintendo’s biggest games versus a hotly anticipated mainline entry to a more niche (by Nintendo standards) franchise.

Hmm… based off of marketing alone, Kirby wins easily. Sakurai knows how to hype up his games, and Nintendo hasn’t done a great job showing off MP4B. However, MP4B is releasing to a massive install-base spanning NS1 & NS2. On top of that, it’s hard to say how well a $70 spin-off game will perform in the long-term.

That said: I’m leaning toward Metroid. Both games won’t have the best legs, but Metroid will have a much bigger launch.

Edit— If Metroid reviews poorly though, then Kirby wins by a wide margin.

I'll get all three but I think all three will sell relatively the same

Metroid might get more LT sales but it'll be close.

As someone pointed out to me on this board awhile ago, Metroid doesn't sell. We tend to forget because we are gamers. But Metroid just doesn't sell. So I'll go with Kirby.

Obviously Kirby Air Riders. It has had actually good marketing and is a much bigger IP than Metroid. As for Hyrule Warriors, I didn't even know that was coming out lol.

With how much of a push Air Riders is getting with two directs focused on it it'd be surprising if it's not that one. After Legends Z-A it's easily Nintendo's biggest game this holiday so a lot more new Switch 2 owners should get it than the others. Prime 4 is also on the Switch 1 which helps it but with how much the Kirby IP has grown lately I doubt that'll be enough and interest in the BOTW universe has declined so I expect this one to sell less than Age of Calamity. I think the only scenario where Air Riders potentially doesn't win is if it has poor reception and Prime 4's reception is excellent.

Either Age of Imprisonment or Air Riders.

Before, I would have said Age of Imprisonment without question because it’s Zelda and it’s tied to TotK. And the Zelda IP’s popularity has skyrocketed since BotW.

But Kirby’s popularity has also shot up thanks in large part to Forgotten Land. And the fact that Air Riders is a game that fans have been waiting over 20 years for AND Sakurai is back at the helm for it AND it’s the first (to my knowledge) Kirby game being launched during the holiday season, those are big enough factors for me to pause and think: Hmm, maybe Kirby will actually outsell Zelda this time. That’d be a first!

Yeah I’m also thinking Air Riders actually.

Air Riders > Hyrule Warriors > Metroid

I’m leaning into the positive and saying Metroid. If we get an amazingly reviewed game this is one of the best chances Metroid has ever had of getting 5 million sales. I think the chances for a positive review (88-92) are very good but that might only get Metroid to 3 million, it’s status quo. A 93-98 would certainly get it to 5 and hopefully “beyond.”