Considering that the former three have already tried the L.A. market before and subsequently moved away, the Jaguars would appear to be the top candidate to relocate.
To be honest, I'm not sure a move to L.A. makes sense for the other three. The Rams have carved out a sizable fanbase in St. Louis, the Raiders are a national brand whose fans seem to identify with the city of Oakland's gritty image, and the Chargers are already the top ticket in a town with enough other distractions.
Jacksonville, on the other hand, would have an opportunity to expand its brand and fanbase into the second-largest market in the nation. Realistically, you can only go up from Jacksonville, a town that has shown minimal interest in the team.
If the Jaguars were to make the move to L.A., one has to wonder whether or not the NFL would have to realign the AFC.
Is it realistic to assume that the Jags would call L.A. home and still play in the AFC South, setting up annual trips to and from Nashville, Indianapolis, and Houston?
I think there would be an easier way, and the NFL would act on it.
The best scenario would be to move the Jags to the AFC West with Denver, Oakland and San Diego.
You would then put the Kansas City Chiefs in the AFC South with Indianapolis, Houston and Tennessee.
It would be tough to get used to, but each of the two divisions would take on a stronger regional identity.
Kansas City, though it has built strong rivalries within the AFC West over the years, really has little else in common with the western cities and fans in their current division. On the other hand, joining the AFC South would mean joining a division full of teams, cities and fanbases much more similar to themselves.
This realignment would make it a little easier for the fans to attend their teams' divisional games and cut down on travel costs, even if just by a little bit, for all 8 teams involved.
It would also give the NFL a chance to develop and capitalize on new rivalries in an old league.