Some episodes that might be able to happen:

1.The team goes to look at kates body one day and it is gone.and then they find out that Kate is still alive but she has just been taken hostage for all these years and needs someone to help her. and Kate comes back to the show.Ziva and Kate fight over Tony,and he has to tell them who he likes more.

2.Ziva and Mcgee go undercover togethor to find out who killed Petty Officer James Brought. While they are undercover they realize being with each other made them both realize how much they love someone.[ziva and tony] [McGee and Abby]. And how much they want to be with them.meanwhile ducky gets a girlfriend.

3.Tony's Mom comes to visit and the team finds out some revealing things about Tonys past.

4.Gibbs Gets ingaged[to another redhead of course]
and then finds out she is the murder to there leading case of 7 dead Petty Officers and has to cancel the wedding before he got married to a murder. He then finds out that she was only marrying him so that she would not be guilty for killing the 7 dead petty officers.

i only have four for now but if anybody could make these episodes happen go ahead i will be truly greatful!