I've had a Lezyne Zecto Drive Taillight for several months now and really like it. Really nice build quality but not super expensive although not super cheap either ($25-30). It has 6 different modes, ranging 2 hrs 45 mins to 7 hrs and has a good battery indicator showing more levels than most so more useful.

Like you I wanted more lights to be more visible, especially since I've started doing more rides at night so I bought a Axiom Pulse 60 Taillight. I've only used it on a few rides but it is very nice and brighter. It has a quick release strap for seatposts and you can adjust the up/down angle so the light is actually pointing back. It was actually about the same price as the Lezyne ($25-30). It has 5 different modes, ranging from 2 1/2 hrs to 7 hrs.

Hope all that helps narrow the search down for a taillight!