There was a thread of someone reviewing the series episode by episode (I forget the topic name but the reviewer was The Habs Fan).
Season 1: The best
Season 2: First half too many cliches, second half pretty good
Season 3: Fine but unmemorable
Season 4: Strong finish
Season 5: Wait, why is there a season 5?
This. Season 1 has many fans, many who stop right there and hate the rest of the series. Those who go on find something decent in most of the rest of the series. Some even say it does have something Season 1 is a bit weak in (the action, the schemes) but everyone does agree overall, Season 1 has the highest quality. Season 2 early on feels like a sci-fi variety pack (trying out every idea from time travel to alternate realities, B-movie bugs, devolutions, etc) but does get better later on. Robert Leeshock, despite being a cheapo replacement does manage to become a watchable lead. Some people have it (Liam Kinkaid, Duncan MacLeod, Hercules, Xena, Mulder, etc) some people don't (Renee Palmer, Highlander: Raven actress, et al). Season 4 tends to be seen as the 2nd best. Many who actually stayed with the series long enough to get there feel that way. Season 5, all EFC fans hate it and many feel it's among the worst seasons of sci-fi ever. Watching Season 5 is an interesting experience. I tried in 01-02, but ended up only half paying attention at times, missed a few episodes, some sent me into a nap, though I did come to for the last few episodes. If EFC weren't such an overlooked show, Season 5 would be legendary in how bad it is.