What are the dif/ferent types of led emitters?

Can someone explain or link to an explanation of the different types of led emitters on the market?
Ive heard of cree xm-l2 gp and a few others and I have no idea what these are or what the emitter specializes in.
ive heard that maybe the xm emitters are more floody? or something along those lines but I really dont know much about the different emitter types.

http://www.candlepowerforums.com/vb/showthread.php?270419-Commonly-Used-LED-Emitter-Index

sticky in this section had a bunch of info. only emitter i currently like is the nichia 219 for the 90cri and 4500k color.

I like the following emitters:

CREE XM-L2 - very bright and efficient. Relatively large die gives a bright floody beam when used in a small light.
CREE XP-G2 - smaller die than XM-L2. Less light, but more intense. Very efficient for its size. Good for smaller lights when more throw is wanted. Excellent for small triple LED lights.
CREE MT-G2 - huge extremely bright LED that produces an enormous wall of light with excellent neutral tint. Fantastic for short-range floodlights.
NICHIA 219B - same size as the XP-G2, but much less efficient. However, the 219B renders colors far better. Also great for small triple LED lights.

All the emitters I named above are successor versions of earlier LEDs (remove the "2" and the "B" for the earlier version). The earlier versions do the same thing, but are slightly less bright.

I tend to prefer neutral tints in the 4000K to 5000K color temperature range.

ok thanks. Also for reflectors I know that in general a deeper reflector makes for more throw, whats the difference between the smooth reflector and the ones that look rough? does the smooth one put out more of the light produced by the led?

The deeper reflector puts more of the light into the hotspot and less into the spill.
The orange peel reflector produces a somewhat larger hotspot but smoother and with less artifacts based on the shape of the LED itself.