Overused graphical effects

[Singularly Datarific]

Jam Blood on the screen when you get shot. It's a handy damage indicator but it seems like every single game needs to scale up the jam factor amount of blood.

It just gets irritating.

I'm looking at you Call Of Duty:Jam Black Ops.

It doesn't look real! It looks like you're looking through a camera!!!
The best one to pull it off was COD4, which just drained vision and turned a bit red.

The greatest offender I've found was looking down sights, and having everything except a tiny portion that you are pointed at entirely out of focus. After about 3 feet, it hardly makes much of a difference, and just looks stupid. I'M LOOKING AT YOUUUU, BORDERLANDS.

EDIT: I've also been looking at how people don't like motion blur. I think it could be pulled off, like a jet flyby, but when you are turning, people's eyes do NOT work like that. Have you ever managed to turn your head, slowly or quickly, and not have your eyes "stick" to something? No. Your brain forces your eyes to look at one point, never to coast around, always to focus on something. To defy that just makes people nauseous. Even when you flick your eyes around to look at things, there are tricks to cancel out blur, in this case, your eyes actually do not see anything for a split second, so it does not blur. That's right: Your eyes BLIND THEMSELVES to avoid blurring the image.

 

[Atmos Duality]

OT: Today, the obvious contenders are Bloom Lighting and excessive Particle Effects (courtesy of Pixel Shader 2, of course). They are quite noticeable when the standard color palette for your average environment is in the darker spectrum.
The resulting contrast might look epic initially (as Gears of War 2 shows), but it gets real old, really, REALLY fast. For examples of excessive/inappropriate use of Bloom Lighting in particular, I cite Mass Effect 2.
Seriously. Half of the game, it looks like there's a divine glow coming from an unknown light source. Light just does not behave that way, no matter how pretty it looks.

The worst offender of all time is actually a game I otherwise adore: Shadow Complex.
It's based on the U3 engine, and so they just HAD to exploit the shit out of it; technically speaking.
Every opening corridor, every water texture, every semi-metallic/high-tech device has this Bloom-Effect on it and it's really distracting. I recall the hallway containing the last (and optional) suit upgrade. It's very white, and oddly lit.
I hadn't seen the color white being violated so strangely since I saw I-Robot.

The only effect that's ever struck me as excessive was the shine in Halo CE. Seriously, everything Covenant looked wet.

That's called Specular Textures+Lighting, and it's the one technical marvel that put Halo: CE on the map. Seriously, Halo probably would not have sold nearly as well if it weren't for that bit of tech, because I've seen what Halo: CE looks like without that (on PC).
It looks like total shit without it, to the point where it actually changes how the game's style looks entirely.

 

[Atmos Duality]

Actually I've got it on PC, it looks like someone sent a squad through the Truth and Reconciliation ahead of you with a pot of vaseline. It's seriously off putting. On xbox it's identical to me (no, I'm not looking up screenshots) but it looked like they'd just figured our how to do the effect and thought they'd do it on everything, it's hideous.

My apologies, I should have been more clear. Back when Halo: CE was ported to PC, I had a video card that did not support Specular Lighting, so I had to play with the effect turned off.
Without specular lighting, the game looks less "wet". With it turned on, it looks like Halo: CE on the Xbox. No real surprise there. (Also, they use specular textures for the Grenade and Plasma effects, so when it's turned off, the explosion radius looks a LOT SMALLER than it actually is, and the plasma weapons look like they're lobbing globs of defective Tupperware plastic).
Still, I do agree with you, the effect looks distinctively alien (like Bungie had this fetish for making everything look slippery and shiny); though the game looks noticaebly like ASS without it.