the other two pistols have longer range but hardly do anything.
M9 Barrett and the Ripper actually have the same power, only thing the Ripper has on the M9 is Multishot, while M9 has Crotchshot.
But for my list I have to say:
Starter: M9 Barrett; Looks cool, shoots the farthest out of all of them, Crotchshot perk, and decent RoF for its power.
Sidearm: Magnum; Accurate, 2 shots to the head kills, so that's 3 kills per clip, just like the Rocket Launcher, a good weapon to switch to when the enemy has low health and you don't feel like wasting your Explosive ammo, and not bad range.
Close Range: Terminator; With the Katana, you have a lethal combination, shoots farthest out of all the close range weapons, god RoF, it's very accurate for how many shots it can put out.
Automatic: Precision Laser; Coolest-looking weapon out of all of them, more accurate than all of the automatics combined, the perk is critical++, (that's headshots, buttshots, and crotchshots) doesn't bounce, and with double damage, it's not to be taken lightly.
Long Range: Holy Grail; One-shot-kill, even if they have adrenaline boost because then the fire gets them, it lights your enemies on fire, it's the most accurate weapon, with double damage, it kills any enemy, with or without shield, 5 shots, and the reload time balances it out.
Heavy: Destroyer; it's powerful and shoots faster than the Shredder, it's accurate for how fast it shoots, it doesn't arch, and it is a demon with the Rapid Fire powerup.
Explosive: Rocket Launcher; It's powerful, with rapid fire, you can clear out 6 AI in no time, 3 shots per clip=3 kills, with Double Damage, it can kill any enemy with or without a shield, one shot can kill multiple enemies, it's accurate from a reasonable distance, and it must be good if that's what Raze Soldier spawns with in lvl 14 of Alien Campaign.