As a player, meaning for fun or rec leagues, when you have a player or team take it WAY too seriously and nitpick on every very minor move of their teammate or infraction the other team does, especially when they absolve themselves of any issue. I'm a competitive player, however I at least recognize the level of play and which violations are major vs minor.
As a fan, I hate the following:
Football - prevent defense - seems my teams usually give up the scores and lose when they bring that out on the field.
Basketball - running down the clock (when the other team still has time) to not setup a play and chuck up a junk shot.
You covered several good ones there ... the rec-league uber-serious teammate and the shot-clock chuck-up are on my list.
And prevent-defense.
Many people have been anti-prevent for a long time, so we aren't alone -- but specifically I loathe it at the end of the first half, especially like this scenario: Team A is ahead 14-3, Team B has managed only about four first downs for first 28 minutes, and almost no plays for more than 10 yards at a crack -- Team B gets ball at its own 25 with 1:30, Team A goes into prevent mode, Team B drives into easy FG range within 45 seconds.