Observing Planets and Comets?

What's a good telescope for observing planets and comets , I'm not eniterly intrested in observing Galaxys,Stars or Constellations.I just want a good telescope that can bring up fairly detailed images of Planets and Comets,I undertsand that I'm not always going to get detailed images because of Atmospheric winds and a number of other things,but I want to be ured that on a Clear night with no disturbances I'll get a fairly detailed image of what ever planet I'm viewing.