The day Modern Warfare 3 came out, my brother went to the midnight release. For the next 3 days, he played it as often as possible. This is easily the most fun-filled (funnest isn't a word?) games in the Call of Duty franchise. It gets rid of most of the stupid frustrating things from the last Modern Warfare and Black Ops. The Kill Streaks are better balanced, and aren't entirely game-breaking this time (chopper gunner and the nuke). Well, there's still osprey gunner, but its not used as much. It actually shows you how many kills you are into you're current streak, so you don't have to keep track yourself. Its very convenient, and its about time they added it to the series.
I also like the fact that there's support kill streaks now, so it continues to add kills to the streak even after you've died. Some of them are useful, but some like ballistic vest are entirely useless. You last one extra second against gunfire, and then you're dead. My favourite is Juggernaut, which basically makes you invincible and gives you a riot shield. Its so much fun to just around absorbing gunfire as the other team panics and tries to figure out how to kill you, as your own team guns them down.
However, most of the time I just you use the regular "strike" package. Since I suck horribly at this game, and can't stay alive for more than a minute, I use the smallest possible streaks. I also use Hardline, since it means I need one less kill per streak. I use UAV, Care Package and Predator Missile, which are 2, 3 and 4 kills respectively. If I have a good game, it means I'm constantly getting UAVs which really makes the game easier. I also like that it cycles through after 4 kills, so if I get another 2 kills I get another UAV. I don't have to die to get more rewards!
My favourite class is one that uses any SMG, although I really like the PP90M1since it has the fastest firing rate ever. Squeeze the trigger and whatever is in front of you dies in a hail of bullets. I use it with:
a Stinger ( Helicopters are annoying)
Sleight of Hand Pro (reloading just takes fooooorever without it)
Hardline Pro ( because I suck)
Steady Aim ( Spray N' Pray is the best. I also don't have the reflexes to do anything but pull the trigger)
This class was specifically designed for my play style of not actually being good at this game. Reloading after every kill is a habit I've picked up from other games, and without sleight of hand its ridiculously slow and tedious. Also due to Halo, instead of looking down my sights, I just fire in their general direction. The kills are still so satisfying.
The Campaign is nothing to write home about. After playing it once, I haven't had the urge to go back to it, which should speak for itself. Its so average. I also don't get shiny numbers popping up every time I do anything, which just isn't as satisfying. If I'm not constantly getting rewarded for something simple, I get so bored of it in this game. I do like the survival mode though. Reminds me of Horde on Gears of War and Firefight in Halo.