There are some people (including myself ) that feel that Season 5 was not as good as the other seasons, but it was the last season that featured overseas missions. My top 3 are:

1) The Amateur. Anthony Zerbe (who also had parts in a Bond and a Star Trek movies) plays a creepy bar owner that accidentally finds part of a McGuffin that Dana had. He then tries to play a spy, but, As episode title says, he's an amateur.

2) My Friend, My Enemy: This one shows Paris being implanted with a device by the bad guys that will try to get him to kill Jim. It gives some background to Paris's life before he joined the IMF, and again had the "what might happen if an agent is disavowed" question.

3)Butterfly: It's not a good episode, but you haven't lived until you've seen Leonard Nimoy play a Kabuki actor.[