Chinese Pistol - DPS: 3 - The Chinese Pistol is possibly the easiest gun to get a hold of in the game, but that doesn't make up for the fact that you'd do more damage by throwing tennis balls at your opponents. There is really no reason to ever use this gun, and since it is nearly worthless to vendors, there is little reason to ever pick one up.
Dart Gun - DPS: 2 - This is an interesting one. This is a weapon built from schematics, and while the DPS from the gun itself is low, what the DPS rating doesn't tell you is that this gun can fire poison darts which inflict large amounts of poison damage over time. A critical with the dart-gun can one-shot most minor enemies in the game. The poison effect also instantly cripples the targets legs, making this a very useful weapon against fast melee enemies like Deathclaws. This weapon counts as a silent weapon as well, so enemies are not alerted if you miss.
.32 Pistol - DPS: 10 - Though twice as powerful as the Chinese Pistol - technically - this little gun still feels rather anemic. You can make do with it for your first few levels, but if you find yourself stuck with it past level 3, you'll need to buy a new gun in a hurry.
Silenced 10mm Pistol/10mm Pistol - DPS:14/16 - These pistols are nearly identical, but the 10mm Silenced Pistol counts as a silent weapon (as you might expect) so firing the weapon won't automatically alert enemies to your presence. The silenced version is also just slightly less powerful. Both of these pistols are good side-arms for the early levels, providing decent punch, and chances are you'll emerge from Vault 101 with a 10mm Pistol in hand, which is why the previous junk pistols are so useless. The Silenced 10mm Pistol can be used at nearly any level in the hands of a stealth-based character, who can use it to pick off enemies one-by-one with head-shots.
Scoped .44 Magnum - DPS: 63 - This is one mean gun, capable of dropping tough enemies with a few shots at a respectable range. Due to its high amount of firepower, it is usable throughout most of the game. The only drawback - and it can be large one - is that .44 ammo is both hard to come by in the Wasteland and very expensive at vendors. As a result, the .44 Magnum tends to be best used as a boss-killer throughout much of the game.