Are both sentences OK?
(a decision etc.))

This is something I was waiting.
This is something I have waited for a long time.

Question

Are both sentences OK?
(a decision etc.))

This is something I was waiting.
This is something I have waited for a long time.

Answer

This is something I was waiting. --> This is something I was waiting for
This is something I have waited for a long time. --> This is something I have been waiting for for a long time.