The best one should be Beijing Tianxing Diaoliang Riding Club. Take the subway from Beijing Railway Station to Dongzhimen, then take 9 15 and get off at Dashanqiao East (Dashanzi) Station. Take 10 meter to stop 988, take 988 to the terminal, take 100 meter to a main road, and Shunbai Road is on the right.
The cost is higher, but it's worth it.