The Skink is your friend. He'll tell you when he's out of battery, but doesn't get all in your face about it. He comes in 6 colours, but won't kick you in the balls if you don't. He'll even cut you some slack if you don't have 4 leds, like him. Just don't bring up his ex. She was pretty much riding everyone's bike and he just gets weird about it, ok?
Features:
Burn time: 30 hours (steady), 220 hours battery life maximum (flashing)