You mean CGI openings? Or in-game engine openings as the game unfolds? Or both? Here is what I can think of by heart right now, I'm sure I'll miss a bunch. It includes openings/intros both with CGIs and in-game engine:
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Half-Life
- In-game intro as you make your way to the test labs.
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Half-Life: Blue Shift
- In-game intro as well, similarly to Gordon's normal day at work, but with Barney now.
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Half-Life 2: Episode One
- From the rubles of H-L 2's aftermath to Alyx's conversation with her dad and finding a way inside the Citadel with Dog, it was genius, part of the game technically but it was also its opening as well, all interactive, it's the magic of the Half-Life saga.
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Half-Life 2: Episode Two
- Not as good as E1's intro, but still well done especially thanks to the surrounding environments, especially when that sudden pulse of energy comes out of the Citadel miles away and you can see it come at you from that distance, followed by the superbly crafted falling/destruction of the viaduct nearby, a technical marvel and still barely seen in games of our days.
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Dragon Age: Origins
- In-game "Origins", presenting the context until Duncan arrives.
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DOOM 3
- Not a fan of the game in general, but I liked the in-game "arrival to Mars" intro.
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Shadow Man
- A forgotten jewel of video gaming adventure, and a nice in-game intro.
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Turok 2: Seeds of Evil
- In-game intro from Adon, followed by a unique intro for each following maps, really nice.
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Crysis
- I liked the intro, parachuting yourself from that plane with your team.
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Dragon Age 2
- Think what you will, but I liked the presentation from Varric until we get to Kirkwall.
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Borderlands
- We get to chose our character from the intro, and then it resumes with the Claptrap and the first few bandits, I liked it.
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Far Cry 2
- The in-game intro was good, I liked it, being cab-driven around the African environment, it set the mood well, unfortunately the rest is history.
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Mass Effect
- Do I really have to describe it?
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Mass Effect 2
- Same as above.
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Warhammer 40,000: Dawn of War
- The CGI intro of the original game, amazing (especially the music).
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Warhammer 40,000: Dawn of War II
- The CGI intro, again, amazing stuff («
This planet is ours, witch!»

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Hellgate London
- I saw it again recently, otherwise I would have forgotten about it, but it's a nice one.
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Total War: Shogun 2
- Beautiful CGI intro.
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Command & Conquer
- Here I'm referring to most of the entire saga's CGI intros (of course often combined with real actors and actresses, it's well known by now), not just from the original's. My favorites are in both C&C 2 (Tiberian Sun) and C&C 3, and some in RA1, R2 and even RA3.
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Diablo II: Lord of Destruction
- Basically, all the CGIs from both vanilla DA2 and the ones from LoD, all great.
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Prey
- Very nice intro, and a bit disturbing when I first saw it, especially when you find yourself inside the alien ship and then try to figure out what's going on as you see other humans being... "processed" as you make your way around, very nicely done.
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Fallout 3
- I really liked it, from your infancy's brief in-game flash-backs to the moment you first step outside of the Vault to see the world with your own eyes for the first time ever, it was truly good looking when I first played that.
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Left 4 Dead
- The CGI intro is great.
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Star Wars: The Force Unleashed
- Yup I liked the intro, please don't burn me alive.
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Star Wars: The Old Republic
- Ok, I'm not sure if those three CGIs so far released are actual intros of the game itself, or intros of specific "chapters" or scripted moments during the game's story development, or if they were "just" made to advertise the game, but either way those CGIs are so good I would see movies made out of them alone, and dare I say it I wouldn't even care if Micheal Bay produced them, bring me what the New Trilogy should have shown me, thanks.
Alright I'll stop here but I'm sure I could think about many more if I took more time for that, but these above just popped in my head right away as the obvious ones.