Formal:
* Considered
* Judged
* Believed
* Regarded
* Held
* Estimated
* Assessed
* Found
* Determined
* Decided
Informal:
* Thought
* Seen as
* Taken to be
* Accepted as
* Viewed as
Examples:
* Formal: The proposal was deemed unacceptable. --> The proposal was considered unacceptable.
* Informal: She was deemed the best candidate. --> She was thought to be the best candidate.
The best word to use will depend on the specific situation and the desired tone.