Might depend on how much you want to spend, and/or how you intend to mount them. There's a ton of different brands and styles to choose from ... including box/bulb styles, box/LED styles, or LED strips.
I use the old style Stan Sloan double bulb (box/bulb) and a BPS single bulb (box/bulb) style blacklights ... w/battery clips & suction cup mounts.