Cop shows that include a 5 minute foot chase. This is usually the result of the cops shouting out a suspect's name from half a block away instead of waiting until they are within arm's reach. Inevitably the suspect runs into the path of a car or truck and the chase ends up being pointless anyway.
Cop shows where six cops burst in the front door of an apartment/house but neglect to post anyone at the fire escape/back door which is the only other exit. This leads to another pointless (and prolonged) foot chase.
Shows where a victim is being chased by a bad guy and manages to knock him down, leaving him momentarily helpless - then doesn't break his kneecaps or grab his gun. Also shows where the good guy and bad guy duke it out while 10 people watch but do not help or grab the gun which has fallen to one side.
Cop shows where the computer geek can instantly cross reference any data from one data base with any data from another database. "I need you to cross-reference left-handed Nazi lesbians with Ford owners in Atlanta who have had a wart removed". Ever notice that on these shows, the computer geek uses only the keyboard?
Shows where the computer geek guesses the password in 10 seconds after glancing around the room.
CSI shows where there is always one bit of forensic evidence that immediately narrows the suspects or areas down to a single person or location. "This pollen is from a plant that only grows in a 20 square foot area in Central Park right next to a homeless guy who matches the description of our perp."
CSI shows where an image can be sharpened to any degree of clarity even if it is a reflection in someone's eyeball. Infinite detail can be created out of nothing.
Shows where the transition music is 5 times the volume of the dialog. Shows like Burn Notice and White Collar are particularly bad for this. It means I have to keep my finger on the volume button. It's like having someone whisper in your ear then suddenly start shouting.
I know that the number of minutes allocated to a show is gradually shrinking. In the 60s, hour long shows actually had 50 minutes of time. Now it's down to 40. This is why closing credits are run at 5 times normal speed, opening themes are now 10-15 seconds instead of two minutes, and opening credits are shown at the start concurrent with the show, but do we really need to space them out over 15 minutes and do we really need to know the names of all two dozen producers, executive producers and co-executive producers? Show me the cast and save the rest for closing.
And in a similar vein, have you noticed that the ads they show during the show (the ones that pop up at the bottom of the screen advertising products or upcoming shows) are gradually taking up more and more of the screen? (some) writers go to a great deal of trouble to create believable plots and get us to willingly suspend our reality to enter theirs. These pop-up ads destroy that mood. It is especially annoying when a pop-up ad obscures something vital to the plot. How would you like it if you were in the movie theatre and every two minutes the guy behind you said "How about a Coke? There's a great movie showing next door in 2 hours. I use Tums. So should you."
Anyone care to add to this list?