When I first got into gaming on the Xbox, Call of Duty: Modern Warfare 3 was where I started. To start off, I played with my sister as I had no hope in 'surviving' on my own! This was about two years ago and I am still hooked! Most of the time, I swap between this game and Black Ops 2 as, in my opinion, they are the best games of the Call of Duty franchise.
One of the best features of Modern Warfare 3 is that it has many different survival maps you can play both solo and with other people. They are based on waves that get harder and harder, and you earn money to upgrade weapons. If you are wanting to get into this game, I would suggest trying out Seatown and Resistance as they have good 'camping' (holding down a small area) areas that you can more or less practice in. Other good maps are Bakaara, Carbon and Village.
Seatown - Survival
Resistance - Survival
The game map is good but it is actually quite short and very. I finished it in about six hours - reading different forums, I found that hundreds of people experienced this as well.
Multiplayer on Modern Warfare 3 is really good as well but for all you 'campers' it is quite challenging when you do not have an in game microphone - unless you are really experienced with the game and can pick up on what the other players are trying to do, it is hard to work as a team with the lack of communication. This aside though, once you find that someone you work really well with, friend request them! It will make life so much easier when you are trying to beat your high scores!
Altogether Call of Duty: Modern Warfare 3 is an amazing game and, in my opinion, is one of the best CoD games out there! I hope you guys have found this interesting - let me know if there is anything else you would like me to try and review!