I found this old draft and have to admit all those company names have been swept away by the thousands of kilometers that followed Colombia. But anyhow, here are the bus companies we either traveled with or heard about in Colombia.
Given the distances and the rather daunting statistics on traffic safety in Colombia picking a good bus company can make a big difference. So here are a few tips based on our experience and advice we have received so far.
The most highly recommended bus company overall is Bolivariano, but it does not operate in all regions of Colombia (we have actually not taken any of their buses so far).
In the Carribean region a very good alternative is Expreso Brasilia which seems to co-operate closely with Unitransco and Caribe Express. We never used Unitransco buses but our experience with Expreso Brasilia and Caribe Express was quite good – clean, new buses, very few stops and less crazy driving than with some other companies.
For the trip between Santa Marta and Vallenato the best company is Costa Line; wide seats, lots of leg space, smooth driving, at least when we traveled on this route.
On the Mompox – Bucaramanga route we were advised to use Copetran but ended up getting on a Cootrans Magdalena bus, which was also fairly new, very comfortable and made only a couple of quick stops.
What followed after Bucaramanga was a rather unpleasant ride to San Gil (lots of curbs on a bumpy road and crazy driving) so the best advice for this route is to try to get on a real bus (Copetran likely again being a good choice) rather than getting a ride in a van (which is what we did) or a mini-bus.
From San Gil to Tunja (where you can catch a ride to Villa de Leyva) we got on an Omega bus (supposed to be a decent company as well) which made quite a few stops and took almost two hours longer than we had been told.
Lastly (so far), we asked several people in Tunja about the best bus to take from there to Bogota and were advised to go for Concorde (first choice) or Libertadores. We decided for Concorde and made it to Bogota in about three hours. The bus was pretty new, clean and comfortable and the driving was perfectly agreeable for the most part.