What is your favorite lighting source?
My favorite one is halogen bulbs, I like its light quality and nice color temperature.

CFL and fluorescent are not my favorite, due to its peaky light spectrum, and the way to render the colors. Also CFLs emmites low levels of UV light, are glary and produces huge armonics of electromagnetic contamination. I like fluorescent tubes under 5000K, over that is just not desirable, even more in CFL.

LED are not my favorite too, since LED have blue overshoots, thing that doesn't happen with incandescent or halogen, and blue overshoots can be harmful, also LED have weird ways to render the colors.

So my frist choise is halogen and incandescent, then fluorescent tubes under 5000K, then good quality LED and the my last choise are CFL bulbs.

CFL and fluorescent are not my favorite, due to its peaky light spectrum, and the way to render the colors. Also CFLs emmites low levels of UV light, are glary and produces huge armonics of electromagnetic contamination. I like fluorescent tubes under 5000K, over that is just not desirable, even more in CFL.

The UV emitted by fluorescents and CFLs is mainly in the UVA, and is very low and within the safe limits.
CFLs and long T5 aren't more glaring than halogen lamps.
Only triphosphors CFLs and fluorescents have peaky spectrum, and they have better CRI than older halophosphor fluorescent lamps.

I like HPS because they cycle at EOL, so I can see the behaviors of the ignitor used in the lanterns and their glow discharge during the cooling down. I also like MH lamps because of the spectrum of it.

The peaky light spectrum does not matter for the color rendering of great majority of things you look at under the light

1. The cone cells in the eye (the cells that see colors in day vision) have a sensitivity band that is about 100nm wide. This means that a light wavelength that hits anywhere on it, will be seen. If it is off center (for example : cool green, that also catches the blue cone cell sensitivity area), both cells will report to the brain that they see light (each in the matching brightness for its band), and the brain will reconstruct it into the correct color

2. The things we look at under the light have a reflection spectrum, thats how they have diffeernt colors. Most things have smooth reflection spectrum - If you light at it with a monochromatic light of X nm, and they reflect something, then at X +- few 10's nm won't do great difference

Together, this leads to that the peaks in the spectrum cannot be seen in msot cases. The exceptions being some things with extremely saturated colors, that dont follow "2.", and they are few and far between

Still, 2700K CFLs and LED doesn't look as far as good as a 2700K halogen bulb to me.

Many 2700K CFLs virtually lack the Blue phosphor, so intear of Triphosphor they are actually "2 phosphor". PL lamps are available at 2700K and 3000K, get a couple and compare them, you'll see quite a difference even though the K temperature is almost the same

Peaky spectrums will overlight some objects, while others will look dim or weird. That's because peaky light sources can't light objects that are not in the peak, or can't render all the color of the object, so eye color response doesn't matter if objects can't light the light can't render all the objects colors. That's why SBMV, MH, CFL, LED and halogen looks so different, even if in your eyes the light looks "white". Because of that there's a "light quality" unit that is the CRI, 100 is perfect and below it becomes worse.

The reflection spectrum of most (even colorful) objects is very wide band, and therefore doesnt care about spectrum peaks as long as they are fairly well spread throughout the visible light spectrum

The CRI is the closest representative to how the light could render objects with extremely saturated colors, which reflection spectrum is narrow band. It is far from being an accurate figure of light quality for most cases. It sorta works when comparing between lamps of the same type (FL vs FL, etc) but fails when you try to put different lamp types with different spectrum on the same scale

This one's been asked before. LPS of course, especially linear 

Mine would have to be incandescent

Real daylight fluorescent with high CRI is my favorite.

Mine would have to be Mercury vapor, both coated and clear, but I'd probably lean more towards coated 

Mercury vapor is my favorite, preferably clear, but if I could have a second choice I would say sodium (HPS and LPS) as well. LED is my least favorite! 

L*D's aren't a light source, they're over-excited semiconductors 

L*D's aren't a light source, they're over-excited semiconductors 

They are a high loss diodes. 

L*D's aren't a light source, they're over-excited semiconductors 

 
Aren't fluro tubes just overly excited phosphors?

(please don't slap me)