I was thinking about doing a speedrun of this game, but then I decided against it because it would be a lot better with two players and I don't have any friends (I suppose I could theoretically control both players, but give me a break here).
Strike Gunner: S.T.G. is a vertically-scrolling shooter released relatively early in the SNES's life in 1992. The thing that separates it from other similar games is the fact that rather than picking up special weapons at the beginning of a stage, you can select any special weapon out of 15 at the beginning of each stage. But you can only use each weapon for one level (per player), so it's important to choose wisely.
With two players, this means you can use any given weapon on two stages instead of one. This is extremely helpful, as one weapon (the Megabeam Cannon) can kill any boss in one hit, and another weapon (the Atomic Missile) can kill half the bosses in the game in one hit. I've done some testing, and I believe I've got a good idea of which weapons to use against which bosses.
(All health measured in Atomic Missiles for some reason, names have been changed because I don't know them)
Level 1 - Giant Plane Dude: This guy technically dies in one Atomic Missile, but you have to destroy all his parts first, which means you'll use a minimum of three Atomic Missiles. I believe the Heavy Vulcan is the best weapon to use against him; it (combined with basic machine gun fire) can kill him in about 15-16 seconds, while the Laser Cannon and Adhesive Bombs take about 20 and 25 seconds respectively.
Level 2 - Giant Helicopter Dude: This guy takes six Atomic Missiles to kill, so that's no good. The Laser Cannon and machine gun will take this guy down in about 4 seconds.
Level 3 - Giant Tank Dude: This guy falls to one Atomic Missile, but you can only use it on two levels, and this guy's the easiest to kill without it. The Laser Cannon, Adhesive Bombs, and Heavy Vulcan all kill him in about the same time (though I believe the Adhesive Bomb is slightly faster), so the decision really boils down to which one kills minibosses faster.
Level 4 - Giant Ship Dude: Normally, to kill this guy, you have to destroy all his little turrets and stuff, then destroy the bridge. But you can get around that by doing enough damage in one shot to destroy the bridge. This can be done with the Megabeam Cannon or the Atomic Missiles. Use the second one.
Level 5 - Giant Satellite Dude: One Atomic Missile and he's down. Nothing special, just an annoying boss that'd take around 11-12 seconds to kill with anything else.
Level 6 - Giant Alien Spaceship Dude: Takes about ten Atomic Missiles to destroy. Use the Megebeam Cannon against this guy.
Level 7 - Slightly Less Giant Alien Spaceship Dude: Despite the decrease in size, this guy is a lot heartier, taking more Atomic Missiles than it's even possible to use. Megabeam Cannon this guy.
Level 8 - Heart of the Mothership or something: This thing isn't even really a boss. It doesn't attack and it dies in a few shots of anything. Pick whatever you want, really.
I think this is the fastest, but this may not be the case. The list is subject to change as new breakthroughs take place.
That only covers the weapons for one player, however. The other player's weapon isn't too terribly important. All enemies (including those missiles that come down at you periodically, if possible) should be killed, but they don't need to be killed as quickly as possible because the game progresses automatically independent of enemies still on the screen (this doesn't apply to minibosses, though). Try to pick something that looks cool, like the Antiair Mines (put these down where enemies will spawn and kill them right as they show up) and Photon Torpedoes (these can be aimed in eight directions). In some levels it may be necessary to use the Sonic Wave or Sonic Shooter to destroy projectiles, as having too many on screen can cause lag (the Atomic Missiles also destroy all projectiles on screen, so keep this in mind).
Also, both players can fuse together to enable a few cool attacks. The player who initiated the fuse retains control of the ship and can fire his machine gun and special weapon as normal, but the other player's machine gun is replaced with a special weapon. When the fuse is initiated with the X button, he can fire bullets in four directions in front of and to the sides of the players. If the fuse is initiated with the Y button, he can fire bullets in one of eight directions by aiming with the control pad. Whether or not you want to use these is up to you.
So, anybody else care to contribute?