>>4573945
I'm going to write down the ideas I had. I'm going to omit the summaries as to why each game is where it is.
RICADO'S ARCADE AUTOSCROLLING SHOOTERS CHART
Most Impactful Games (If you haven't played the genre and want to know which games were key in this genre's history)
Honorable mention: Space Invaders by Taito from 78. I won't be listing single screen 2-way movement games, however.
82/83: Xevious (Namco)
84: 1942 (Capcom), Star Force (Tehkan, Tecmo)
85: Tiger Heli (Toaplan), Gradius, Twinbee (Konami)
86: Salamander (Konami)
87: Flying Shark, Twin Cobra (Toaplan), R-Type (Irem), Darius (Taito), 1943 (Capcom)
88: Image Fight (Irem), Truxton (Toaplan), Gradius II (Konami)
89: This year is mostly refinement afaik
90: Raiden (Seibu Kaihatsu)
91: Again, mostly refinement, I think
92: Aero Fighters (Video System)
93: Batsugun (Toaplan), Raiden II (Seibu Kaihatsu), Sengoku Ace (Psikyo)
94: Gunbird (Psikyo), Raiden DX (Seibu Kaihatsu), Rayforce (Taito)
95: Strikers 1945 (Psikyo), DonPachi (Cave)
96: Battle Garegga (Raizing), Sengoku Blade (Psikyo)
97: DoDonPachi (Cave), Zero Gunner (Psikyo)
98: Radiant Silvergun (Treasure)
99: Giga Wing (Takumi), Gradius IV (Konami)
00: Mars Matrix (Takumi), Dragon Blaze (Psikyo)
01: Ikaruga (Treasure), Zero Gunner II (Psikyo)
02: DoDonPachi DaiOuJou (Cave)
03+ (retro only): Ketsui (Cave), other Naomi titles (Companies: G.rev, Milestone)
Most other Namco, Taito, Toaplan, Capcom, Konami, Cave, Psikyo, Raizing, Irem and Seibu Keihatsu shooters come recommended, and I'm sure some anons will add games from other companies that had less impact but still made some nice shooters (like the Data East shooters just as an example)
This is less based on personal favorites, since mine is probably Dogyuun.