First Please clarify about your familiarity with types of microcontrollers...
Do you know All microcontrollers well?? means AVR, 8051, PIC and many more.
IF you are good at Atmel AVR series than typical Arduino (arduino UNO)will be right choice.
If know PIC than go for it....
If you are completely beginner.....than prefer arduino....BCoz....Arduino hides Initial hurdles generally faced by beginners regarding uc's
1)programming interface...
2)detail knowledge of its architecture.
3) complex programming structure.
In fact this initial difficulties keeps beginners frustrated.
there are lots of resources available of Arduino(books,videos, completed projects),
there are lots of library...
and of course easy to use arduino shields for various applications which will solve hardware dificulties.
!!!! Arduino is a board which enables even non-technical person to make great projects....!!!!