Here's the basic costs I found NOT including regulatory requirements for building new plants:
Solar (voltaic)- $6000-$10000 per KWP with a very low maintenance factor. Large footprint per watt. Variable output.
Microturbines (can burn any liquid or gas petrochem) $1000-1500 per KWP. Low maintenance (overhaul every 4th year), small footprint per watt.
Fuel Cell-$3000-4000 per KWP. Moderate maintenance. small to moderate footprint per watt.
Wind Turbine- $1500-$3000 per KWP. Moderate maintenance. Very large footprint. Placement critical. Energy output is variable so requires other/backup generation sources that are in addition to those KWP.
Internal Combustion $400-$900 per KWP. Moderate maintenance. Small footprint. Can use Gas, Diesel, Liquid Natural Gas- so it's flexible and can be plumbed to use whatever source is cheapest at the time.
Fossil Fuel/Coal $500-$1000 per KWP + additional costs for 'clean coal'. Moderate maintenance. Small footprint. (huge hurdles legally)
Nuclear has been very expensive based on the American Model however the smaller footprint models Europe has been using have been much cheaper. Westinghouse quotes a price of $1400 per KW for the first plant and $1000 for subsequent plants and it's modular. The American Model has been the big plants like you see in pics of 3 mile island. Here is the Westinghouse model
http://www.ap1000.westinghousenuclear.com/.
*Edit: and on hydroelectric, I couldn't find a good summary like this. However it's traditionally considered very cheap overall. They have high initial costs but no further fuel required. You can say that's the same for solar and wind, but water tends to be much more effective and more consistant.
*Edit #2, I found the direct info on Coal Cost I was looking for from the Connecticut Integrated Resource Plan:
Overnight capital cost (2008 $/kw) Electricity cost (cents/KWh)
nuclear ............................. 4038................ 8.34
supercritical coal ................ 2214............... 8.65
supercritical coal +CCS......... 4037.................. 14.19
As you can see, Coal is cheap up front, but then the ongoing cost of fuel plus Carbon Capture and Storage technologies really pushes coal through the roof.