General:
* All: This is the most common and versatile alternative.
* Each and every: This emphasizes the inclusiveness of "everything."
* Whole: This implies completeness.
* Entire: Similar to "whole," but may emphasize a single unit.
* Total: This emphasizes the sum of all parts.
Specific:
* All things: This clarifies that we're talking about physical objects.
* Every single thing: This emphasizes the comprehensiveness.
* All that exists: This emphasizes existence.
* The universe: This emphasizes the vastness of "everything."
* Everything under the sun: This is an informal way of saying "everything."
Figurative:
* The whole shebang: This is a colloquial expression for "everything."
* The whole kit and caboodle: This is another colloquial expression for "everything."
The best word to use will depend on the specific situation. Consider what nuance you want to convey and choose accordingly.