The Cygolite is one of the few that combines bright with long run time, IF you use the flash mode, because its flash mode is very brief, probably a 5 or maybe 10% duty cycle.

The downside to the Cygolite (and the reason I won't buy anymore, but I do use the one I have) is that the beam is very narrow.

In general bright = less run time.

The really long lasting lights are the ones that run on AAA cells, like the Planet Bike Superflash. It was considered a bright light a few years ago but it doesn't stand up to modern rechargable lights. Still, it's probably pretty good in many environments and it will run a lot of hours on a set of cells.

I like to run one constant and one flashing. I use a Pulse 60 on steady mounted on the bike, and a Cygolite on flash on my helmet. Neither of those are long-lasting in steady mode though. I just am used to charging everything frequently. I need to bring my helmet in to charge both front and rear facing vid cams anyway, so I just plug in the Cygolite every 3 or 4 days, and if I've used it, the little tiny headlight that's on there too. The headlight battery comes off the bike every 2 days, and I pull the Pulse off then and charge it as well.