The first season is definitely the most conventional (for the time) and I think that reflects in some of JMS's statements saying the show was still getting onto its feet through the first season. Having the serialized story was very unfamiliar territory for Hollywood television back then, they were learning on their feet.

If I recall correctly JMS wrote basically every episode after season 1, where as season 1 had a few guest writers. The guest written episodes did not do well, including episode 14 which is probably the worst episode in the entire series.

The "TKO" 'A' plot is silly but it has one of the most moving and memorable 'B' plots of the series!

Season 2 had a similar writer split to season 1. It's season 3 where he took the reins entirely.