Trailers are very important for video games. Since mainstream gaming is mostly a shallow vacuous money driven image of asthetics, it's what sells them. Along with currupt media lying. This is my list of games that had awsome trailers with the game itself actually being really crappy. Big turds. 1 is the best trailer. 5 the least best (but still the best).
1. Assassin's Creed Revelations
This has a cool trailer. Full of emotion and all that crap. Ubisoft is very good at promos. Most games they make look awsome. But in reality, most are garbage. This game is garbage. A re-hash of an already overrated game that doesn't deserve million of sales. Also drm. Matrix ripoff. Waste of time.
2. Metal Gear Solid 2
This is actually the intro of the game but it was a teaser used. It makes it look like you play as cool dude macho man. In reality, you play as Leonardo Dicaprio man boy. I was very hyped for this game and ran out and got it on day release. Even imported it but the thing wouldn't work. Sadly, I didn't realize the entire thing was a movie. Well, not a movie, like a badly written anime episode stretched out to about 30 hours. The trailer is cool because it short. After hours, it just becomes annoying. Overall, terrible game, good trailer. Metal Gear Solid 3/4 also suck but this has a good intro/trailer.
3. Mass Effect 2
This launch trailer stole music from Titanic. I played the original game. It seemed average at best. Like a fool, I gave into the hype. All this talk about "it fixed the problems". "It's amazing best game ever". No, it is terrible. You go round collecting people like pokemon and keep them in your pokemon area (like all Bioware games ever). It's suppose to be this amazingly emotionally engaging experience. Bioware themselves claim they are attempting to make "the most emotionally engaging games ever". Sadly, every character sounds like a Vulcan or Data from startrek. Characters who have no emotion. Overall, this is gears of war if it was in space more and even worse.
4. Grand Theft Auto 4
Grand Theft Auto 4 sold millions and millions. It was gods gift to man. Critics fapped like mad until they had a face like a light bulb that had taken LSD. Or so it appeared. The game is like Grand Theft Auto 3 without the fun. Thats all you need to say really.... short but accurate description. The trailer is great. But thats because it is a total ripoff of "Koyaanisqatsi". Overall, boring game.
5. Dead Island
Much like GTA4, this trailer is a ripoff of "The Scientist" from Coldplay. Coldplay probably ripped it off as well. Either way, this is ripoff. This game is best described as "stalker" without the scares, tension, or fun. It is really crappy. It is mostly melee based but still very boring. At the point of release, I was already sick of zombie games. But this is probably the crappest zombie game I have played (outside of Resident Evil).
Feel free to suggest your own.