If you're talking about seeing something before its release:
* Review: This implies a more comprehensive and critical analysis after the release.
* Finale: This refers to the end or conclusion of something.
* Full version: This is the complete and final product.
If you're talking about looking at something before doing something else:
* Review: This implies looking back at something after it's been done.
* Recap: This is a summary of something that has already happened.
If you're talking about a sneak peek or a short clip:
* Full-length: This refers to the complete and unabridged version.
* Entire: This also implies the complete version, without any omissions.
The best opposite will depend on the specific context and what you're trying to convey.