Wind Waker made me buy a Gamecube.

Dragon Age Inquisition for PS4 but that was more, I wanted the game and just needed to move to the next gen.

I also want to add there were a couple of games in the 90's that made me get a whole new PC.  This may not make as much sense anymore, but in the 20th century, the PC had a huge crapload of great exclusive games that never made it to console.

Civilization 1 - I convinced my dad I needed a PC for college, but the main reason I wanted one was to play Civ 1.

Ultima Online - I bought a new PC with the latest modem (56k baby!) to play Ultima Online.

This is why I sometimes say, you can charge any amount for a console as long as the games are good enough.  The PC has had some fairly incredible exclusive games over the years, and I've known people (not just me) to get a new PC to play a certain game.  Gaming is first and foremost about games.  If your system has great exclusive games, then people will want to buy it even if it is a really high price.

I bought an Xbox for Halo: Combat Evolved. I went with a friend to a LAN party and bought the system along with a copy of the game the next day lol.

Mowed lawns that entire summer to save up for a PS2, only to find out about Halo! 

For me...

- Super Mario Galaxy sold me on the Wii

- Gears of War sold me on the Xbox 360

- Uncharted 2 sold me on the PS3

- Bayonetta 2 sold me on the Wii U

- Super Mario Odyssey sold me on the Switch

FF7 for PS1
Capcom vs Snk 2 and Resident Evil Code Veronica for Dreamcast
Phantasy star online and Metroid Prime for Gamecube
Lost Odyssey for Xbox 360
Recore and Ori for Xbox One

Super Mario Odyssey for me on Switch.
Kingdom Hearts for PlayStation 2.

-PS2, for Mega Man X7 (being honest is really tough. Yes, this game made me buy a PS2, it was depressing at the time but thankfully i quickly remembered what i originally wanted. Legacy of Kain: Soul Reaver 2.)

-Game Boy, for Donkey Kong Country

-Xbox, for Halo and Doom 3

-Xbox 360, for Gears of War & Halo 3

-Xbox One, for Killer Instinct 2013

-Dreamcast, for Soul Reaver and Shadow Man (Great ports from the original platforms)

Looking ahead, Hellblade 2 is looking like the game that might well get my to pull the trigger and get an Xbox Series X, if it turns out to be as great as the first game.

FF16 and Valkyrie Elysium might get me to really try and get a PS5.

Melee is what got me to get a Gamecube and made a lifelong Nintendo fan.