I had an LED light kit from the Space Cities Panteras crew which I've been really pleased with, but I felt the brake lights were a little underwhelming. They were about equally as bright as the original filament bulbs, but definitely no brighter. I would love a set of Jon Haas's brake lights, but don't have room in the budget for those babies since my engine swallowed the air cleaner stud last year and is being rebuilt, AGAIN.
Anyway, in my quest for brighter brake lights I found a review and recommendation for Red Plasma LED bulbs from West Coast Cougars. They're a bit pricey as far as a pair of LED bulbs goes, but I thought I'd give them a try. Anyway, they are definitely brighter than my old LED bulbs! And they're much brighter when viewed off-angle than the old LED bulbs were.
http://www2.cougarpartscatalog.com/plasma2.html
You can probably find some cheap Chinese versions of the same bulb, but supposedly the guys at WCCC tested a number of different ones with less than satisfactory results before discovering these.
The Plasma LED bulb on the left actually appears brighter in person than in the picture, but you can still see that it's brighter than the standard SMD bulb on the right.
The bulb on the left is the Plasma LED, and the bulb on the right is the SMD LED (old style).
Even off-angle, the Plasma LED bulb is brighter!