Let's start this discussion here...
http://www.curvemeister.com/support/curvemeister2/help/Wizard/CSMatrix.htmFor a quick overview of the color spaces and the strengths and weaknesses. This is by no means a difinetive explaination but it does open the discussion quite nicely.
As for me personally, I use LAB for a large amount of the images I work on. It usually converts to prints very well. I have a few exceptions but mostly they are my mistakes and not a failure of the color space. I find myself being much more careful in RGB or CMYK due to the complete ease of adding a color shift to the images.
To me LAB is the most intuitive because the lightness is separate from color. I can play with the contrast and detail controls without adding a color cast. I used to only use RGB. I found myself working far too often to fix my own mistakes. For me personally LAB cures that to some extent.
Please feel free to expand on the discussion with your own feelings about this as well as asking more about the question after you have read the article. You will most likely have more questions...
Good question by the way...
Greg