I currently have a nitepro elite and a titan and have previously owned the nightpro. The elite is an excellent helmet light for the money. Its simple battery and light setup is really nice because its hard to forget something when you pack up early for a trip plus with only two pieces, there is less to go wrong.
The nightpro was nice but I found that I never used both of its lights at once, the high beam completely washed out the wide angle so it wasn't really necessary. Also, with the nightpro, when it gets super cold (below 5-10 degrees) the glue holding the bottle battery together falls apart. This was more of a nuisance than anything because the pack never came apart while riding.
The titan is nice with its varying light output. My only gripe with it is that the battery is kind of heavy but if you use a camelback you shouldn't have a problem but in a jersey pocket its sort of a pain. This is the light that I use for all of my commuting and it has proved reliable.