USB rechargeables on the helmet because they're very lightweight:
Vivo Bike Illuminati white front (there are similar models that cost less)
Blackburn 2'Fer rear red
I run both in flashing mode. They last about 4-5 hours and recharge at the same rate, so it's easy to keep up with.
On the bike front itself (handlebar or fork, depends),
Serfas SL-255 (seems to be an honest 255 lumens at maximum brightness). Takes a pair of AA, alkaline or NiMH. About 5 hours on maximum. With alkalines it runs a bit longer but the light gradually dims so you don't get full output for 5 hours. With NiMH it's nearly full output until it goes out suddenly, but lasts a bit less time per charge than alkalines. Not the brightest but a good value if you prefer a AA powered light. Durable and seems weatherproof so far. I recharge the NiMH or swap alkalines about once a week. I'll run it on medium brightness in some areas to milk the batteries a bit longer, up to 7-8 hours.
On the rear rack,
Planet Bike Rear Rack Blinky 5, combo 5-LED red and good sized reflector. In videos and photos from group rides it's more visible than technically brighter single point rear red LEDs because of the lens design and horizontal placement of LEDs. Runs a long dang time on a pair of AAA batteries. I may change batteries once or twice a month, depending on how many long night rides I do.
However the Planet Bike Blinky 5 is sometimes unavailable or on back order. If you like the idea of a red LED/reflector combo, check out the Serfas Stop Sign or TL-STP lights. Both look good for the money.
My next bike-mounted taillight will probably be the Cygolite Hotshot Pro 80 USB rechargeable for daytime use. It's very bright, almost too bright for nighttime use, but an attention getter in daylight at a good value at under $40. It's visibly brighter than the PDW Radbot 1000, PB Superflash -- I've seen all three lights together in local group rides. There are brighter lights but they cost more.
I've also begun carrying a $15 Jackery USB external battery/charger (recommended by friends locally, and a very good value in the crowded USB external battery market). Works to extend the run time for any compatible device, including my iPhone 4s, Ion Speed Pro video camera, and USB lights. But it's not weather proof and not convenient to use with helmet mounted lights. So it's mostly for fair weather use with my video camera, or as a recharger when I've stopped to eat or rest.
And my next AA battery headlight will be a B&M Ixon IQ Premium. The exchange value makes it a bargain now and there are a few US importers and a couple of German exporters, all reportedly reliable. I want something with a well shaped beam pattern rather than the common flashlight type circular pool.