Depends on battery type.
On regular 1xAA, the Rexlight 2.0 is the brightest I've seen, followed by the Ultrafire C3 and Fenix L1D-CE. See my review of the multi-level lights here:
Rexlight, DX X.1 & X.V, Jetbeam MkIIX & CLE, Fenix L1DCE review: RUNTIMES + BEAMSHOTS
On 14500, the DX X.1 or Jetbeam MkIIX are the most bright, about 70+ on my output scale. Haven't test the L1D-CE since 14500 is not officially supported. Output on the Rex 2.0 or C3 is a lot less. I plan to do a review of the new single output lights soon.
Oh, and the Cree Elly is at it best equivalent to the L1D-CE. I've had or moded 5 of them, and they all wound up between 70-100% of the L1D-CE initial output.
BTW, I'm talking total output above. If you mean throw, the L1D-CE wins hands down due to its smooth reflector.