Currently Online 
Developers like there effects to make a game look more realistic, or rather make it look like it was shot with a camera (which really doesn't make sense in first person perpective) They usually go overboard though, I guess trying to hide low polycount and low res textures, and end up simulating the crappiest digital camera you can think of.
Chromatic abberation
Starting of with an effect that's gaining popularity, chromatic abberation. In the real world it occurs when a cheap lens is used with a short focal point. Light of different wavelengths focus at different distances making it hard to get a fully sharp image, and you end up with color bleeding. In videogames it usually simulates the effect of a badly calibrated CRT monitor where red green and blue get seperated. It's not realistic, and don't bother making it realistic because it simply is ugly.
Example: Alien colonial marines
Motion blur
Is it ever realistic? I turn if off when ever possible, it just makes things harder to see. It's a camera slow shutter effect, not something your eyes suffer from. Objects that you look at and track do not have motion blur, unless they are spinning. Keep it limited to wheels, helicopter blades, etc. I've never seen anyone's arm blur when throwing a ball, or the world turn into a blurry mess when I turn my head, or drive at 200 kph.
Example: Riptide
Bokeh depth of field
A lens effect used to highlight parts of a scene. Great in photography, or even cutscenes, not so great during gameplay. The game doesn't know what you're looking at so you end up with either always having a blurry background, or very jarring changes. For example in Uncharted 2 while aiming through a fence, when the crosshair hits the fence it's almost like someone hit you over the head.
This screenshot also shows vignette, usually just darkening of the corners in games, pointless.
Example: 3D dot game heroes
Bloom
I never liked bloom, sure you get some bloom in real life while driving into the setting sun for example, but games take it to the extreme. Most of the time it just results in an ugly bleeding effect, aka video bloom.
Example: Syndicate
HDR High dynamic range lighting
Closely related with / responsible for bloom. Yes when you walk outside everything looks a bit bright at first, and a bit dark when you go into a dark room, but as with eveything else games dial it up to 11. White out skies, completely white exits of tunnels or buildings, totally unrealistic. HDR in photography works the opposite as in games, used to capture the full range instead of blocking out parts. In human vision, you're either squinting for a few seconds, or color is a bit off for a short time when coming inside after being out in the snow in the sun for example. Actual human night vision takes much longer to adjust to.
Example: Lost coast
