Tangenting completely from my usual theme of satirising the ridiculous inflation in usage of certain weapons, I've decided to catalogue a trio of perk combinations which might prove useful to you.
Note that these are of my opinion only and may differ from your hardline COD-first opinions which are results of continuous days studying play strategies (and growing a beard from not getting up off the lounge.)
A Sniper's Dream
Simple: equip Blind Eye, Assassin, and Dead Silence. Blind Eye will stop you from being targeted by any annoying helicopters or sentry guns in the rare times that your Vitamin-D deficient sniper skin sees the light of day (thanks to your in-game character being inside all the time). Assassin, the biggest help here, stops those pesky UAVs, Counter-UAVs, thermal scopes, sentry guns and EMPs from affecting you (although the more wily Recon Drones can still hit you, so watch it!). And of course, Dead Silence stops you from being heard. Like a little kid ("little children should be seen and not heard!") To boot, it reduces the affects of the Assassin penetrating Recon! With this combination, you can snipe... without too much detection.
This is a tried and tested set (from yours truly): Scavenger, Assassin, and Sitrep. Think it's terrible? Not quite. Scavenger helps you last a lot longer - you resupply and keep going. Simple. Assassin (as I just stated) stops you from being detected/affected by UAVs, Counter-UAVs, thermals, sentries, and EMPs. Just watch your back for that Recon Drone. And Sitrep stops those lovely Airdrop Traps from being sprung in your face - and helps you on Hardhat, where people put Claymores and Bouncing Betties down like candy. This'll help you become like me!
I see this set all the time: Sleight of Hand, Quickdraw, and Stalker . It's all about speed. Sleight of Hand, as you may know, makes your reload quicker (and if you were bothered to unlock Pro, it switches your weapons quicker.) Quickdraw reduces your ADS time - this is really helpful in CQC. And Stalker works with Quickdraw - you'll move much faster when ADSing with Stalker (Stalker Pro delays Airdrop Trap detonation, yippee!) If you want to be a commoner and "fit in", use these Perks.