Tom Riker said:
Exogenesis
A standalone episode that is easily my least favourite of the season. However, despite it's non-arc storyline, I liked a lot of the ideas in this episode. The fact that all the "victims" turned out to be willing volunteers was a nice twist on a worn sci fi premise. On the minus side, the parasitic aliens themselves seemed like a ripoff of the Trill. I'm sure the fanboys on the DS9 side of the fence had a field day with this episode.
Messages From Earth
Amazing. Lots of stuff comes to a head in this episode, while at the same time more plot threads being built for future episodes. The flashback story that the scientist tells is very suspenseful and creepy. The White Star/Shadow Vessel battle is very cool. Sheridan took another step away from Earth Force. Is this going to lead to something bigger? Regarding the Nightwatch plot, Zack is going to have to make a choice as to what side he's on. And then there's the end with President Clark declaring martial law. This is my favourite episode of season 3, up to this point. However, the next two episodes look like they might be even better.