Formal:
* Discriminating: This emphasizes the ability to make fine distinctions and choose carefully.
* Fastidious: This suggests a high standard of cleanliness and orderliness, often applied to taste or choice.
* Particular: This implies specific preferences and a reluctance to accept anything less.
* Selective: This emphasizes the process of making choices based on certain criteria.
Informal:
* Picky: This is a casual and often used term for someone who has high standards.
* Fussy: Similar to picky, but often implies a tendency to complain or be difficult.
* Demanding: This emphasizes the expectation of high quality or service.
* Finicky: This refers to being very particular, often in a way that's considered excessive.
Other:
* Prudish: This implies a reluctance to accept anything that is considered immodest or vulgar.
* Squeamish: This describes someone who is easily disgusted or offended.
The best synonym to use will depend on the specific context and the tone you want to convey.