So many good candidates
Huey Teocalli and Chiczen Itza are rarely useful, if even buildable on most maps.
The great lighthouse feels like it offers little, especially because you don't need the sea movement and admirals to easily beat the AI in naval wars. While navy itself feels weak because all the good cities are inland.
The mahabodhi temple is a terrible way to invest production into anything. Missionaries are only really useful for religious victories, and if you're dedicated to that, you won't need two more.
Some of the late game culture wonders have too small effects to even be noticeable. I don't even remember what they do.
The hanging gardens has almost no impact when it hits, since you're usually housing/amenity capped until the lategame.
The Venetian Arsenal, while really strong (OP) on say multiplayer naval maps, ends up doing very little in most singleplayer games, because you'll never make up for the production necessary for it.
The great library, while it has the writing slots, feels wrong to build because you can never make use of its boosting ability. Not to mention that you usually don't want to build campuses that early with the current state of balance.