51 / AVR single-chip microcomputer with what good?

51 / AVR single-chip microcomputer with what good?
http://www.siliconray.com/arduino-pro-mini-with-atmega328p.html
I see taobao, at sixes and sevens, what minimum system ah, what download of the kind used these do not understand, want to buy a neat a piece of board good good study, please recommend, had better have followed the mark, the ultrasonic, wireless, remote control, infrared, human body detection, text display, steering gear control, some that all, thank you
The best answer the proposal with 06:55 51 series microcontroller, user huge, routines is rich, the example to learn range is very wide, and domestic STC series 51 SCM too fast, the same crystals, average speed can reach the original 8 to 10 times, and bring their own 8 and 10 AD, converting speed fast, a subtle can be completed all the way AD transform, serial communication baud rate I now work in 115200 is very normal. The most convenient is software can ?