If you mean "lacking interest":
* Boring
* Dull
* Tedious
* Monotonous
* Uninspiring
* Unengaging
If you mean "unremarkable":
* Ordinary
* Commonplace
* Mundane
* Typical
* Unremarkable
If you mean "not worthy of attention":
* Unimportant
* Insignificant
* Trivial
* Irrelevant
Choose the word that best fits the specific context of your sentence.