Most Significant Video Game innovations?

Over the last 3 decades (EDIT: generalised to reflect all time)... video games have evolved tremendously.
 
What in your opinion are video game milestones that deserve recognition.  It can be something as simple as Pong... simply for making video games known or Myst for concept.
 
Personally, the Myst series has always been one of my favorites for innovation.  They always seem to try to bring out new ideas for video gaming and try to push the envelop a little more each time.

Probably Xbox live, to be honest.

The original id team. Everything that modern shooters are are owed to what those guys started.

3 decades?! Bit limiting. 
 
Imo the two greatest innovations in gaming history were the life bar and the introduction of online achievements.

"  the life bar "

" @The_A_Drain said:

"  the life bar "

i laughed. "

" @Ahmad_Metallic said:

" @The_A_Drain said:

"  the life bar "

i laughed. "

How come?  I was 100% serious :P "

The technology that made 101001010011000011000001001001's into this
 

• Side-scrolling
• 3D games
• Networked gaming
• Analog sticks / Dual analog sticks

Physics engines getting better and better would be mine. Ragdoll physics and Euphoria+Rage engines. Running people over was made a billion times better with those.
 
You can pin dudes to walls in Half Life 2 with the crossbow due to ragdoll (and you can pin their flailing limbs too), which is hilarious, and hitting people in cars was revolutionized in GTA IV. So was falling down stairs while drunk, pushing people down stairs, and pushing dudes into trains. I never thought getting drunk and trying to climb up 4-step high stairs would be so amusing. Or tripping over a curb.
 
Also, the Havok engine (Mercenaries and Mercs 2 ftw).

" Physics engines getting better and better would be mine. Ragdoll physics and Euphoria+Rage engines. Running people over was made a billion times better with those. You can pin dudes to walls in Half Life 2 with the crossbow due to ragdoll (and you can pin their flailing limbs too), which is hilarious, and hitting people in cars was revolutionized in GTA IV. So was falling down stairs while drunk, pushing people down stairs, and pushing dudes into trains. I never thought getting drunk and trying to climb up 4-step high stairs would be so amusing. Or tripping over a curb. Also, the Havok engine (Mercenaries and Mercs 2 ftw). "

" The original id team. Everything that modern shooters are are owed to what those guys started. "

Physics engines and their licencing models as opposed to individual development for each game.

Not sure if it counts, but Steam. Without Steam many, many good indie games would go unknown. 

" I'll assume you mean of all time because I'm totally not looking up dates:
 

Any answer that isn't "3D" is wrong. That brought about a total change to the ways people made/played games.

Cartridges. Imagine if you had to buy a new console for every game you wanted to play.

Save games. You complain that games are too short now, but I mean before you HAD to beat them in one sitting otherwise you'd have to start over, so they took like 2 hours to beat.

" Save games. You complain that games are too short now, but I mean before you HAD to beat them in one sitting otherwise you'd have to start over, so they took like 2 hours to beat. "

Online multiplayer

Limb systems.

3d, online gaming anduhhhhhhhhhhh, sprint button?

" Limb systems. "

Pretty much everything Nintendo has done controller-wise which their competition has copied. I'm not giving any love to motion controls, though, because they still suck.

I'm of the opinion that the modern video game was invented in the SNES/Genesis era, so I suppose those consoles are significant milestones. It was around that time that developers shifted from arcade design philosophies to something more accommodating to a longer at-home game experience.

The N64 Analogue stick.

3D (not actual pop out of the screen 3D, but the change from 2D to 3D)

Services like the MSN Gaming Zone before games could look at server lists 
Dedicated Server hosting
CD media instead of cartridges 
The bug in Street Fighter 2 that created combos
Most things Sega tried to do before they were considered a good idea (sega channel->xbox live/psn demos, sega saturn/dreamcast modem->xbox live matchmaking, etc)

" @LackingSaint said:

" Limb systems. "

Do you mean Inverse Kinematic Rigging, or Ragdoll Physics? Or both?  "

Also, sex mini games.

Smart folks have said this but X box live (because it has changed the way that video games are made asking developers to create BOTH a compelling single player and multiplayer experience) It also democratized online gaming away from the PC world to the general masses.

Please note that part of me wants to scream out Neo Geo for bringing the full arcade experience into the home. Another part of me wants to say Gameboy by basically setting the benchmark for portable gaming.  The rest of me says virtual boy.  Its  a good question though for what is the most IMPORTANT as opposed to most innovative.

Real human emotion.