Call of Duty Modern Warfare 3

The Campaign is a continuation of MW2. You start out as Yuri, who is with Nikolai. Eventually, Soap will die and Price is told Yuri knows Makarov. The campaign is a usual campaign. You also play as Frost, and even Price near the ends of the campaign. I didn't enjoy this campaign like the compared to the other ones but it is a good play through.

Multiplayer

It is not very like so far and it has only started. People are complaining that the spawns in this game are not equal and they spawn by an enemy and die. They also do not like the type 95 as it is overpowered. The prestige's go to 10 just like the other Call of Duty's. The max level is at the highest yet at 80. Gold guns are also in this CoD, but instead of max prestige you have gun levels. And to unlock the gold you have to max level the gun for the gold cammo.
 
Spec Ops

Is back again with missions from the campaign. They are fun and single player, split-screen, and even with an online person. But there is a new mode called Survival, it is like Zombies in surviving the rounds. Except you level up, to unlock things to use and guns. You use money instead of points. The Survival has a lot of maps to play compared to the Zombies from World at War of Black Ops.

Call of Duty Black Ops

The Campaign is a continuation of Call of Duty World at War. You play as Mason and only play as him. The campaign is an average game. It is a good game. The story line follows through very nicely you will not get lost as it shows you your being interrogated. And they ask you (Mason) about certain things he has done on his missions.

Multiplayer

Is fun it is not as campy and complaining as MW2 was there are new kill streaks. And even gold guns in the end of the prestige's  there are 15 instead of the usual 10, if you wish to have the gold guns then 14 and 15 is where they are unlocked. Unfortunately, they cost a lot of money ($50,000) since buying attachments is no longer kill count unlocked there is a monetized system set up to where buying from earned money is set up. But this game is fun to play and I myself really enjoyed this game and had a lot of clocked time in the end of its life.

Zombies

Treyarch does not have Spec Ops like Infinity Ward, instead they have Zombies. Zombies started out in CoD World at War. It is a favorite of mine, there is not end to zombies as it is believe since it continues until all players are downed. This game mode can be played by yourself, in split-screen, and online with a maximum of 4 players in a lobby.

Call of Duty: MW2

This game is a continuation of Call of Duty 4 Modern Warfare. The Campaign starts out with you as Pvt. Allen, in the middle east. Then you switch to Roach the other playable character. There are some great things in this game I myself believe this campaign had a good story line and really great action.

Multiplayer
The multiplayer on this game is an average, there was some things a lot of people didn't like for example the One Man Army noob tubing (grenade launchers). So if you want to get away from that there tends to be less of that in Search and Destroy.

Spec Ops

Is another way to play the game. It contains missions from the Campaign, these are fun to play. You can play them by yourself with another person in split-screen and even with someone else online.