Either get a dynohub now or never, ever, ever buy one. Because, if you get one later, you'll look at all the lights that are gathering dust in a shoebox and wonder if you could sell all of them without a buyer thinking they're stolen.

I would recommend the IXON IQ. It has rechargable batteries AND it can be hooked up to a dyno at any point in the future. you basically get the best of both worlds. If you want an astonishing amount of light that will last on battery power for many hours, get two IXON IQs (magicshine is good too though, as many have mentioned).

Whatever light you get, the REALLY important thing is that you get fork mounts. Lights mounted low on your forks will cast deeper shadows making pot holes and rubble more obvious. In fact, get the fork mounts before you bother getting new lights.
https://www.sheldonbrown.com/harris/lighting/mounts.html

Another happy Magicshine user here. It is a great light for the money. It is not quite as sophisticated as the $300-$400 lights, but offers much of the performance for a fraction of the price.
I also use a Planet Bike blaze 2w in flash mode up front, day or night, and only use the magicshine after dark. If I'm in a heavy traffic zone in daylight hours I'll put both front lights in flash mode. People notice me, which is what I'm after in the daytime.
In back I use a combination of the Planet Bike Superflash and the PDW Radbot 1000, both in their flash modes.