Of the ones on the list, I'd say 2007. Halo 3, Mario Galaxy, and BioShock were all amazing generation-defining games to me, with the latter two being my favorite games of that generation.
But overall, I'd say 1991. The SNES released in the U.S., and games like Super Mario World, Final Fantasy IV, F-Zero, Super Ghouls & Ghosts and Gradius III were released that year alongside or in the first several months afterward. The Genesis had Sonic the Hedgehog, Streets of Rage, Turrican, and Toejam & Earl. The aging NES was still getting solid titles like Battletoads, Metal Storm, Power Blade, and Ninja Gaiden III. And Street Fighter II was lighting up the arcades in what would be among the last few boom years for arcades in the U.S. before they started to decline in the latter half of the decade.
The 90s were probably my favorite decade for video games, and 1991 was to me the best year of that decade.
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