Here's my take, for what it is worth:
I've been buying some LEDs on ebay and Xmas light strings from local stores to hack the LEDs out of them.
So far no joy from ebay sellers with LEDs that average 10 cents each. They are not horrible, but they are not leading in brightness and they are too blue.
I've done much better with the X-mas light strings as I can sometimes test them in the store first. The best strings I've found were warm white LEDs Sold at Menards. The are the bare 5mm LED that were a 70 to a string. The other was Sylvania (?) sold at Home Depot. These have a little plastic globe over a the LED that pulls off. These are 3mm LEDs so are rather wide angle and put the others I tried to shame in total light output. They are not as bluish either.
The best 5mm LEDs I have are the 15 deg 18,000mcd LEDs I brought from superbrightleds two years ago. They are bright and not too blueish. Too expensive, however. Another is the Radio Shack LED. Two to a pack for $2. Too expensive, but very different. The have a warmish 4,100-4,500K color temp similar to Osram's "Golden Dragon" LED. They are too wide angle for flashlights though.
I guess my quest for good low cost LEDs is limited to hacking apart X-mas light strings. You can get LED for 12-18 cents each this way and no shipping wait.
