Best combination of LS and optics?

LD, HD, NX-05, Fraen LP, Fraen -whatever.... So many to choose from and some I don't even know about.

What combination gives the brightest, tightest, whitest beam? LD with Fraen, or HD with NX-05, or ....?

Does there need to be an offset distance between LED and optic or can it sit directly?

I sort of remember one combination gave a very tight beam, but the hotspot was square instead of round. Is this typical, undesirable, can be worked around?

Thanks in advance.

tightest, brightest, would be 30mm optics and a HD luxeon. Get 30mm from Wayne over at Elektrolumens. Optics sit directly on top of the led. You may need to wiggle them side to side to get the led centered perfectly. Only time you'd need to space the optic from the led is with a 5W since it emits light in a different "pattern". There are no real good optics for 5Ws right now. Other than the special Fraen made for 5w. (not the low profile one)

What size can it be? If you are looking for small, 30mm won't be it. Next brightest in size would be Fraen lowprofile on a HD luxeon. It has virtually no side spill, but a big bright hotspot. the side spill is squareish that it does have.