I don't know if these are the brightest but they are close as far as dropins go.
http://www.malkoffdevices.com/shop2/index.php?main_page=product_info&cPath=1_12&products_id=27
http://www.batteryjunction.com/tle-300.html
anybody? not three LEDs even though i do appreciate those posts i am looking to make an aspherical mag and would prefer a single LED because i think that three would not provide that nice beam if i am wrong let me know thanks. and no i am not tied to a drop in. just looking for a LED super thrower that i can make myself. thanks