#11 Half-life 2 played on PC, released 2004
For me Half-life 2 has the perfect balance of Exploration, Experimentation and Extermination. The atmosphere is amazing right from the start. Arriving at the station with Dr Breens propaganda was brilliantly executed. The oppresive nature and the realistic setting immediately set the tone for the rest of the game.
Not long after you get to leave the station you get a chance to experiment with the physics. At the time the game released, realistic physics were still very new. I spend half an hour in the little playground right at the start. It was fun playing with bricks and putting stuff on the merry-go-round to watch it fly off realistically as you spin it up. Weight, friction, momentum all beautifully working as they should.
Valve are masters at story telling without using cut scenes and it really shows in HL2. Facial animation can still easily compete with todays titles and all the little body gestures are still done better then in todays titles which gives the characters a lifelike human nature.
Exploration is best catered for during the vehicle sections. I stopped everywhere during the boat and buggy sequences. Checking out all the beautifully lit locations. The structures and houses along the way felt real and offered plenty of opportunities to play with the physics. For example stacking up tires, or stuffing furniture down the fireplace and blow it all up with a grenade. I spend another hour playing with the crane later on in the game. After killing everyone by dropping or launching containers at them, I started stuffing things inside the container and watch it all fly out realistically while swinging the crane around.
The action side of the games is well catered for too. The epic fight under the big bridge for example, trying to defend your position in the prison and the whole end sequence of the game. Ravenholm is the chapter where all 3 elements come together the best. An awesome playground to explore and experiment with all different kinds of ways to kill. The gravity gun is at its best in this chapter.
The 2 follow up episodes are excellent as well. HL2 deathmatch was fun too although it suffered from lag. Shooting toilets and radiators at eachother provided a lot of good laughs.
HL2 has so many great moments, no wonder Valve feels intimidated by it. Topping this is going to be hard.