I just ordered the new "GQ GMC-320-Plus Geiger Counter Nuclear Radiation Detector Meter Beta Gamma X ray test equipment".
This NeClear Radiation Detector is very poplar around the world. It has a USB conectivity to the PC, which also charge the battery. You can operate as a handheld stand along device or via a PC software. It can display the radiation levels in several ways, including a 60 seconds Histogram graph. It can record and playback the measurements. PC connection lets you view and store the outcomes of the measurements, create graphs and many more.
Seem very nice product with lots of users and good reviews.
There are 2 models , the basic GMC-300E and the more advances( more memory, faster) GMC-320P.
GMC-300 (usually going for ~$100):
GMC-320 (usually going for ~$118):