I thought "The River of Souls" was a very good Babylon 5 movie, with some exceptional performances from Martin Sheen, Tracy Scoggins and Ian MacShane. If this were an episode of the series (without the humour) it would probably be one of my favourite stand-alone stories of the series.
Personally, I've always preferred Scoggins to Christian, although granted JMS didn't write her as well for much of the series and she did have to endure the Byron/Telepath plot. If you take out the smutty humour about the brothel and the "poorer" actors in those scenes, then this movie is solid stuff. Probably my third favourite of the four movies, but in no means bad at all.