When I went to Chengdu I stayed at the TRAFFIC HOTEL or JIAOTONG FANDIAN (phone: 5451017) which is situated on the riverside of the Jin Jiang next to the Xinanmen Busstation. They offer dormitory for 40 Kuai, which is a nice and clean 3-bed-room. Clean showers and western style toilets.
There are cheaper places like the Sams Backpacker Guesthouses 1+2 with prices around 30 Kuai, but during my stay they were crowded, booked out, so I could not check the quality.
But the Traffic Hotel convinced me being worth the money!
It still is a walk of 15 minutes to the core of downtown but therefore you are close to the busstation leaving for the Big Buddha DaFo in LeShan and the EmeiShan.
It is a pitty that a bad stomach stopped me from visiting the DaFo! I will always remeber Chengdu as the place of my worst diarrhea - but the good toilets of the Traffic Hotel were certainly a big help;-)

If you go to Xian pass by the Railwaystation quarter as soon as possible. There are many hotels (next to all these hairdressershops....) but they are of poor quality.

The best one I could find was the CHUYUAN Hostel Phone: (29)-7287721. It is situated right at the NanMen - the South Gate of the City Wall. Take Bus No. 603 from the railwaystation to the South Gate. Walk to the right side of the Gate, just before passing through the Wall take the last alley on the right side - it is a small path only for one car at a time. Less than 50 meters and you will find this great place.
Everything is in an old traditional style, really cute. Employees are very young and helpful. They are all dressed in traditional clothes which fit to the architecture of the building.
They are also quite flexible with prices - a double room cost us 100 yuan.
They also offer a nice cuisine for afordable prices, even though I always prefer the streetkitchens throughout the Muslim Quarter.
The location is just perfect, when you get out of the Hotel doors you run right into the Great City Wall! You can not get any closer with your bed!
It is only a five to ten minutes walk to the Bell tower, the center of the old city.
Enjoy your stay!

Despite offering some amazing cultural and historical sights, Datong is not that famous for tourists, so there is no huge number of places to stay.
We arrived in the dark with heavy snowfall and missed the Hostel right opposite to the trainstation.
We first stayed in a more expensive hotel on the main road for 150 Kuai a doubleroom (for Datong quite expensive).

The next day we changed to the FEITIAN BINGUAN, which I mentioned is opposite to the trainstation on left side of the suare. They charge 40 Kuai for dormitory. Facilities are ok, toilets in Chinese style.

The pic shows the more expensive Hotelon the main road, sorry I can? remeber the name...