Mario 64 seems to be the most common mention so far. Wonder if there's a correlation between people who enjoyed some of these launch-systems growing up and therefore have a higher standard for launch libraries compared to those who have not received consoles at launch.
Saturn - Virtua Fighter
Dreamcast - Soulcalibur
OG Xbox - Halo CE(Halo 2 is better though)
PS2 - Tekken Tag Tournament
Xbox 360 - PGR 3
Xbox One - Killer Instinct
Probably Jooxed
can give some insight for Nintendo consoles.
Off the top of my head, Nintendo usually had at least one:
NES - I'm not sure if Super Mario Bros counts. It was a launch title in America but the NES had already been out for 2 years in Japan.
Gameboy - North America launched with Tetris
SNES - Super Mario World
Sega Saturn - the US launch had Panzer Dragoon
N64 - Mario 64
Xbox OG - Halo
Wii - Wii Sports and Twilight Princess
Switch - Breath of the Wild
Gamecube, Wii U did not. Interestingly, Gameboy was the only handheld that had one.
Hmm. Luigis mansion which i appreciate more and more with time, mario 64, twilight princess (cheating, as someone already said though, gamecube ver was better as well)
Lastly even though I wasnt alive for the launch, f zero on snes.
Wow, before looking at the list I would have said one or two but up until this gen it’s much higher. Duck Hunt, SMB, SMW, F-Zero, SimCity, SM64, THPS3, ExciteTruck, NFS Carbon... there are a bunch that I had a lot of fun with!