Traveling by bus is definitely one of the best and cheapest ways of traveling in Mexico. Even the luxury buses, with private TV, wireless internet, big seats that fully recline and air-conditioning are very affordable. To give you an example, a six hour ride in one of these luxury buses (Mexico City-Guadalajara) would cost you 20 Euro. If you would go by air it could easily cost five times that amount.
You can reserve your bus on the internet or at the bus station.
Selection of the best bus companies:
Boda ReAl 