As IT suggests you won't go wrong with systems like Gaugemaster Prodigy Express, NCE Powercab, or Roco Multimaus. I beg to differ slightly on one point with IT, NCE Powercab is one of the most user friendly DCC controllers on the market and famed for its ease of use. To get a spread of information and opinions on DCC suggest have a look at threads on the UK's RMWEB as it has a larger user base than here in Ireland. http://www.rmweb.co.uk/community/index.php?/forum/21-dcc/
Suggest you avoid PC/Laptop based systems as they lack the tactile feel of a throttle/cab with its buttons and knobs.
Some images of cabs below. Cab/Throttle ergonomics is a very personal choice, arrangement of buttons, knobs, sliders, throttle control, display, function buttons if using sound, weight, feel in hand, portability, etc. The first three are priced as starter systems.
Guagemaster
NCE
Roco - best of the toy brands (beats hornby and bachmann)
Zimo - More expensive high end system
Lenz - The best of the best
ESU ECoS 50200 - The ultimate top of the line in DCC console based systems
Cheers
Noel