one example ...
This is an example of a wide-angle HUD from one US company's 737:
The largest portion in the center is the attitude indicator w/horizon bar and Flight Path marker.
There's also a ton of other things, mostly along the sides/periphery which indicate:
Airspeed, Vertical Speed, Baro Altitimeter, trend vectors, wind velocity, Speed Error, Flight Path Acceleration, Slip/Skid, Flight Director modes, Nav Data, and a few more items.
While it's quite a bit of data presented (some might say too much), the HUD will de-clutter depending on the phase of flight. For instance, during a low-visibility approach, many extraneous items are deleted so that the pilot can focus on the "important" information.