Free: Contests & Raffles.
The Liberty Mystic X is one of the most adaptable suppressors available for different calibers, and mine is very quiet. Some other suppressors are better at specific things, but the Mystic covers a lot of bases pretty well. It'll handle most pistol calibers from .357 down, and a lot of rifle cartridges too. Nothing bigger than 35 cal of course, as it's a 9mm suppressor. Be aware that there's a big difference in noise between a suppressed 9mm and a suppressed 45 Auto, and most suppressors fired with 45 Auto are still somewhat loud/sharp sounding unless you add ablative. 9mm is a lot easier to suppress really quietly in a pistol. Long barrels are generally easier to suppress too.Also be aware that blowback actions (like most pistol caliber carbines) don't suppress as well as a locked breech action, because of noise from the ejection port. That varies for individual guns of course, but for example, my 16" Beretta Storm carbine (9mm) is louder than any of my 9mm Glocks when used with the same suppressor and same ammo. Another "universal" suppressor that sounds interesting to me is the Griffin Optimus, but I don't have any personal experience with it so I hesitate to say more.
x2 on the Liberty Mystic X. I have one and love it. I can swap it between my 9mm, .22 LR and .223's. My 9mm suppressed sounds slightly quieter than a .22 LR non-suppressed and a .22 LR suppressed sounds like a pellet gun
We all have our preference but for the most part, they all make a good can. Some may be a little lighter and a little quieter than others and generally you'll pay more for those that are, but most of them are good. It's not to often you see or hear about a suppressor that people say, those suck don't buy that one. Personally, I prefer the cans that are modular and you can shoot them in a short or long configuration.