I figured I'd explain why I chose my permanent unlocks.
1st) Ghost. Pretty self explanatory. The UAV spam was ridiculous and luckily, I had the game on Saturday before release, so I was able to get close to 55 before the actual launch, so I had ghost when everyone else was spamming the UAV's. It makes such a huge difference when you run ghost.
2nd) MSMC. Best gun in the game for me. I used it before it was known to be 'over-powered' as I had the game early and I've been using it ever since. It's the gun that I'm most accustomed too and it's similar to the AK-74u from Black Ops 1, which was the only gun I ever used.
3rd) Scavenger. Again, self explanatory. I hated running out of ammo and I loved the fact I could keep using my equipment/grenades over and over. Must have perk!
4th) Orbital VSAT. It's like Porter said, it's the best overall scorestreak in the game. It's just great, there's no other way to say it, so I decided to unlock it after I got my class ready beforehand.
5th) Swarm. You only ever get to use this for like 2 ranks if you prestige and if you level up as fast as I do, it's a very short time. Every time I equipped Swarm, I got it. So I wanted to unlock it and I can say it was a great choice. It's an epic streak, except most people back out when you call it out
6th) K9 Unit. Similar to the Swam, while not as good. I like using K8 with Swarm because you can still Run&Gun and don't have to sit there controlling a scorestreak, which I find to be very boring. However, I've found that the Swarm often dwarfs the K9 unit, so it's best to call them out separate sometimes.
7th) I'm currently rank 50 f 6th prestige, so once I do prestige, I'll be unlocking the C4 simply because it's so useful in many situations. To those who use it, you'll understand and i you don't use it, you need to start!