I preferred the bus ride as usual. In Turkey there are several bus companies. You can go to the central bus station and choose one of them. Usually the big ones go almost everywhere. Some companies are more reliable/safer and have better service than others. VARAN is one of the famous but more expensive. I used many times PAMUKALLE and METRO that are very good too.
The bus station(otogar in Turkish) is not far from the center.
I used Pamukkale, a good reliable company from Istanbul. The bus ride took about 6 hours, the bus stopped in the middle for 20 minutes for refreshing. I payed 30YTL(18euro).
For my ride to Goreme I used Nevsehir Seyahat. The ticket costs 25YTL(15euro).


