If you mean fixed at one end, I gave you a couple of examples in your previous thread.
Many buildings use the concept.
The cross section of many bridges use the concept.
Telescopic cranes use the concept.
Flag's poles use that concept.
A fishing rod is just that, fixed to the hand of the fisherman; same for most tools, pens, etc.
Anything that is more or less horizontal and is not supported at both extremes in order to avoid falling, could be considered a fixed beam.
If you mean fixed at both ends, then we can find more examples:
A walking bridge between two buildings.
The section of any bridge that is located between two contiguos supports.
Pipe supports anchored to two columns.
Structure of steel buildings.