I like them both. Both have weaker first seasons than the rest of their runs. B5 has a lot of foundational episodes in the first season, planting seeds for later, but they feel very episodic. Whereas Farscape is pretty much episodic, with a few seeds.
If it matters to you, Farscape's effects are much better than B5's and most of the acting is better. B5 feels like a product of its time--which I'm not saying is a bad thing, it just is and for some that's important.
Its hard for me to choose. If Star Trek is in the lead, then maybe B5.