Money. It "can be exchanged for goods and services", but useless by itself (and there are certainly those who've acquired more of it than they could possibly ever use to purchase things), and seeking it causes all manner of intrigue and zany schemes.
Diplomas. Technically, they are meant to represent the accomplishment of a certain level of education. By themselves, however, they are just paper. Which, naturally, is why forged degrees from shady online universities are so popular.
Especially during the holidays, namely when trying to buy a VERY popular toy for the kids.
Every scavenger hunt since the beginning of time was just a list of MacGuffins to be collected.
The ball or similar item used in most team sports. During the game people try to gain control of it, so as to score points. The team that scores the most point in some arbitrary amount of game-time wins the game. The number of regular season games a team wins is generally used to determine the rankings in a play-off tournament at the end of the year. Whoever wins the games in each level of the tournament advances through the rank to the championship. Winning the championship gets you a shiny trophy and nebulous bragging rights, which mostly expire round about the beginning of the next season. Then it begins again.
Almost everyone is looking for or are trying to maintain a partner, sex and a sense of importance/power. These can be personally fulfilling on their own. However there are certainly those who seek these things only because everyone else seems to desire them a lot.
Dogs will generally compete for thrown sticks and other objects the held no importance until they were thrown.