You know the ones that from the moment you got in your grubby little mitts till you finished had you giddy as a school girl. That totally knocked your socks off from the intro to the ending.
Xwing and TIE Fighter(not "vs." i mean the originals that came in about 20 floppy discs): Oh the sweet intro cutscenes with their awesome midi soundtracks! Angry blaster toting personnel making sure you signed in your password! Sure looking back the low poly models and textures not deserving the name might be a bit dated but at the time? Bliss from start to finish, everything I could ever want from a Star Wars game.
Hexen II Beyond Heretic: First Person Melee set in this medieval fantasy realm. This was probably my first bloody game, and boy was it fun. Featuring a pletethora of fun weapons, from lighting axes to magical powers and a special item that turned you enemies into piglets. The environments were absolutely beautiful featuring complex puzzles to progress though the multi zone levels. There was this one ice level with strobing lights and big nasty yeti monster things that used to scare the crap out of me as a kid.
Journeyman Project: Time Turbo and Buried in Time: Ah I miss the point and click adventure games, and these two were excellent examples. Graphically they were complete eyegasms, even today there isn't much I could complain about in terms of the visuals and audio. Thats pretty good considering Presto Studios released them in 1992 and 95 respectively. The stories and puzzles were excellent, even today I will occasional take them out for a spin. As a member of the Temporal Protectorate you were charged with protecting the time stream, and boy was it a fun job.
Duke Nukem 3D: Hail to the King Baby! The perfect blend of one liners, violence and debauchery. What else is there to say? cept maybe shame on you 3D Realms.
Rebel Assault II: Where else could you fly a YT1300 balls to the walls through a bloody mine shaft? At the time for me this was a graphical tour de force, the full motion video was amazing. From the intro following the mouse bot around the corridors to blowing up that massive asteroid facility I was hooked.
Total Annihilation: Probably my favorite RTS ever. A few RTS games come close, Dawn of War in particular, but I still will dig out the old disks and create some mayhem. The rumbling advance of Bulldogs, the whithering fire of Brawlers and the thunder of Big Berthas all combine into this great destructive adventure. If I were to only have a few games to play for the rest of my life TA would be one of them.
Dark Forces II: I remember it distinctly because it was the first game I got after a major computer upgrade. When I saw the FMV intro zooming through Nar Shadda to see Kyle Katarn dealing with a shifty droid I knew I was not going to be disappointed. Nor was I, in a few ways I think DFII was even funner and more epic then Jedi Knight. The story, the environments complete with civilians, the weapons everything was just fabulous. It all combined into an adventure that seemed much more grandious then Jedi Knight, even if the latter did perfect much of the light saber combat and force powers.
FreeSpace 2: This was another benchmark game for a new computer. From the beginnings of the Gregorian sounding vocals through the flyby of the Colossus I was just wowed. That greatness continued into the first training mission when after shooting an amazon i noticed the particle spew. Holy Crap there are flames shooting out of my weapon strikes! I was also impressed with how fleshed out the "verse" was when i visited the techrooms. The campaign was magnificent, the impetuous bravado of the GTVA running into a solid wall of unbeatable Shivan strength was very well executed. Everything about FS 2 was top notch from start to finish.
Call of Duty: The original, when WW2 Shooters were not done to death, and I couldn't navigate Carentan despite never being there. It just had plenty of great moments, those scripted events COD does so well where amazing the first time out. The perfectly recreated boat trip over the Volga was right out of Enemy at the Gates. Not to mention the multiplayer, oh good times indeed.
America's Army: Oh the free multiplayer goodness. This game was a staple of my college multi gaming. So many little things were just great, from the ringing after affects of a grenade going off close by to needing to unjam your weapon. Plus the original photo recon Ranger mission in the depot? Being the last remaining member of your team running around the halls in Night Vision? Probably the only game ever that actually got my adrenaline to pump.
Knights of the Old Republic: I remember standing out in the street on Taris being deliriously happy I was in a living breathing Star Wars world. Statement: There isn't much I can say about KOTOR that hasn't been said master. May I splatter the meatbags' organs all over the floor now?
Half Life 2: I picked it up late with the Orange Box so it came with the extra episodes. If ever there was a game that made me feel like I was living in a dysotopian hell hole post alien invasion it was HL2. From regimented City 17 to the gutted hulks of beached ships i totally bought the environments in Half Life. It also scores high marks on making me care about my fellow NPCs. Kudos Valve, i hope Episode 3 rocks hard whenever it comes out.
Portal: One of the most unique things I've played in a while, All the obscure cake jokes Axem prodded me with to get it was well worth it. The novelty alone makes it stand out but the execution of it made it a big wow for me, albeit a short one. The cake was a lie, but does that mean there was grief counseling?
God I miss full motion video cutscenes
Well thats my list, now these are complete knock your socks of games, I've left off plenty of good ones that either grew on me or didn't have the complete impact from frame one. For example I consider Dawn of War one of my favorite games ever but in terms of wowing the crap out of me from the get go it didn't cut the mustard. So I'd like to hear some of everyone else's.