Powerful, sleek, and comfortable to hold for long periods of time, Fenix is a flashlight brand you can look to for products that will last for a good long time. Though they like to come up with many upgrades to their old ones, so keep an eye out for those.
One of these upgrades is the BC30R. While itself a little outdated, this is still one of the better options for a bike light you'll find. Shooting a neutral white 1600 lumen beam at max both out on the road ahead while lighting up your wheel at the same time, this rather tiny light uses a built-in li-ion battery for power. The BC30R's power and mode buttons have a back light and sit right below an OLED screen that lets you know how much battery life is left and the mode you're in.
A new light from Fenix is the RC11. This light includes the 18650 needed to power it, and is charging compatible. The 1000 lumen beam is useful, but you'll find the RC11 works better when hung on a metallic surface thanks to the magnetic tailcap. Holding it longterm is easy, and the area around the button and charging port bevels in for comfort and grip.