Ares light fire 75: A light pistol with low damage (6) and average base accuracy, this gun costs a packet but has several good points that might be argued to make it worth it. First and foremost, it comes with an integral smartgun system. Nice, but hardly unique and lets face it if you want a smartgun pistol then the Predator V is a far superior choice most of the time. This weapon's main strength is that it also includes an integral silencer, meaning that (by a straight reading of the rules) it can also take a gas vent system as the integral upgrade doesn't use up its barrel slot. If you want a silent light pistol with a gas vent then this is your gun, but with it's price tag I can't really say that most people will favor it.
Ares light fire 70: The bare bones version of the 75, this gun sacrifices all the automatic upgrades to give you the cheapest light pistol in the game. once again it's damage isn't great, but it's base accuracy is top-tier and its endurance is solid with a 16 round clip. Though the special silencer isn't standard on this model you can still buy it as an extra, and it's 25% more effective than an ordinary silencer at +50% of the price. Personally, it's a solid all-rounder and a good throw-away due to its price.
Beretta 201T: Low damage, average accuracy, and a price tag barely higher than the light fire 70, this gun's stand-out features are a larger 21 round clip, a detachable stock and, the big one, burst fire capacity. If you want a concealable carry weapon but aren't really that skilled with pistols, this gun is a solid choice for you.
Colt America L36: High damage, high accuracy, classic. If this gun has a flaw it's the weapons endurance, with a measly 11 round clip. If that doesn't matter to you then this is arguably a contender for top light pistol for you.
Fichetti Security 600: High damage, average accuracy. This is a badass pistol that comes standard with a laser sight and a folding stock, along with a staggering 30 round clip! A less accurate design and marginally more expensive than the Colt America, this weapon compensates with the largest clip capacity of any light pistol and a highly useful folding stock to help with recoil. Good gun.
Taurus Omni-6: This is a gun with a split personality, so I'll give it two reviews. The common factors are the worst accuracy of any light pistol, lousy ammunition capacity, and a laser sight included in the package. Most wounding is that it cannot mount a silencer due to it being a revolver, so it'll probably be gas vented if you're in the mood to mod such a pistol.
It's first personality is a semi-automatic pistol with low damage, no internal compensation for recoil, and as mentioned before lousy ammunition. add a gas vent, and it can lay down two semi-auto bursts before you reload.
The second personality is a SS pistol with the best damage (ok, technically best AP. either way it's the hardest hitting) of any light pistol. Not bad at all due to the rules for SS weapon. Might be worth it if you don't care about stealth but for whatever reason have to use a light pistol.
to sum up, they're all fairly well rounded and each has their own niche. have fun