Previously remarked on SuperBright LEDs. These are still excellent value but the Ultra LEDs lot have stolen a march on them - latest one from Ultra has 19 axial and 16 radial LEDs for a total of 35, the important bit being that they are 26mm dia. and fit normal bulb housings. They're more expensive, at about 8 quid each (cf about 8 dollars) but worth the extra, I think.
I got a pair of these to try out in the minibus and they're sufficiently impressive that I've just ordered some more - 2 more amber and 2 of the similar 30-LED (18 axial, 12 radial) red ones for me brake lights. I'm happy with the superbright ones for rear/fog lamp - but their 24-LED amber one is not impressive in an indicator housing. I emailed them to say so, but haven't seen any new products...
Ultra do a 35-led one for rear/brake appications in red, as well.
I see their latest offering is one with 16 LEDs all radial which they say is ideal for the jewel-type modern car lamps.
no connection, with either company. Ultra seem to be the way to go for indicators, especially, at the moment.