MOST SUPRISINGLY GOOD GAME
My first award goes to a game which I played which was much better than I expected it to be. If you have never tried this game, or have heard about it and are curious about it, I recommend giving it a try!
Runner Up
MONDAY NIGHT COMBAT
I bought this game based on a recommendation from a friend and was pleasantly suprised. The gameplay is fun, action-packed and most importantly, very well balanced. There aren't many game modes to play, but the few modes you can play are great fun, and are perfect distractions to play in between whatever main game you are playing at the moment.
Despite some lag/matchmaking problems this game is an excellent arcade game and well worth the price.
Winner
JUST CAUSE 2
After being very impressed with the demo, I went out and bought Just Cause 2. It's improved so much on the first game it just had to win an award, the gameplay is fun, the game world is still massive, yet no where near as empty as it was in the prequel. The game is packed with things to do outside of the main missions, and getting to a mere 75% completion took me deep into the 60s hour mark.
I spent a lot of time playing this game, whether it was messing about, going for achievements or doing the main story, and despite some weaknesses, it's one of the funnest new games I played in 2010. Definately try the demo if you haven't yet, I guarantee you will enjoy it, and likely will want to get the full game afterwards!