What is 'Good' energy?

What exactly is Good energy? is Wind better than Solar? Is Hydro ok? What about Nuclear or Carbon Capture and storage?
Most forms of renewable energy are generally thought of as good and most fossil fuels are thought of as bad. Where does nuclear fall in this range? Atomic energy after all emits no C0₂ (at least during power generation) but it is not normally seen as all that safe.

Is it suitable to look only at the carbon emmisions of a technology to determine if it is good or not? should other things be considered? Wind farms seem to be the most economically accessible - each turbine can be built for a relitvely small investment which will pay for itself within the lifetime of the device - but some people think they are a blot on the landscape and the fact that they are often in mountainous (and therefore picturesque) areas makes this worse. I think they actually look quite majestic as they slowly turn generating 'clean' power.
Tidal power is another similar issue, the severn barrage could be built to produce nearly 10% of the UK's electricity requirements but in doing so would adversely affect a delicate ecology. Is this good? (would the ecological balance be affected by global warming anyway?) At least tidal power is predictable.

Solar power, wind power and wave power power are not prdicatable - geothermal power is not very viable in the UK (so far as I know) Are we always going to need some dirty power as a base load to cover when tidal power is at an ebb?

I don't know the answer to many/any of these questions. If you do let me know