You mean "spray-on" tight. Never. Well, almost never. I can't think of when they would be appropriate. People can see that you're "well built" without being able to tell if the quarter in your pocket is heads or tails.
This will highly depend on your taste and your gender. Tight jeans will go well with ladies while well fitting jeans will go well with guys. However, you can go with the policy that says "if comfortable, wear it".