Enum, Joins, or Strings

This is just a quick database design discussion. When you encounter a field in a database that can take on one of a set number of values, how do you handle storing them?

Let me give an example: A database that has a table for cars stores the condition the car is in. Say the options are: “New”, “Excellent”, “Good”, “Average”, and “Bad”.

The way I see it there are 3 options here in storing these conditions:

  1. Create a separate “condition” table with a relationship between that and the car table. This means you can associate more information with the condition.
  2. Store the condition in an enumerable type with the ecto enum library. Postgres handles the validation and such for you.
  3. Store the condition as a string and do all validation and such on the server side of things. This might be the simplest, but it’s a lot less flexible.

What do you all think is the best approach and why? Under what conditions would you choose one approach over another?