Smasha's UltraFire TH-T60 looks a lot like the flashlight I have that is now in ultra-dim mode.
It gave me no trouble at all until last week.
I got mine from DealExtreme, too, but I'm not ordering from there any more. I got one DX light (another 18650-powered light, this one with a red LED that I used for a taillight) that was DOA. I got a replacement, but it was a bit of a hassle. Not condemning the company, and I know many people here have used DX with great success, just expressing my preference.
Now, that Nitecore ... what a light! Guys, check it out.
A lot of engineering went into that one. I've never seen an LED flashlight that could go red, green or blue light (blue, for blood-stain detection!)
The switch is in the ring behind the light head. All of my flashlights have the push-button switch in the end, which seem to vary in quality and reliability.
The Nitecore page did not give a price for "The Revenger." I'm guessing this is not a $30 flashlight.