If you are looking for a pocket size light, perhaps one of the Malkoff MDCs? Malkoff was mentioned by a couple of previous posters, but I don't think this specific model. Pocket size, clicky, and a nice deep-cary clip. He has models taking a single CR123a, Li Ion 16340/RCR, or AA (which wil take a 14500, but you loose the low mode.) I have a couple of these and they are very nice, for about $100 a piece.
Another pocket light possiblility is a Peak, perhaps a Logan? From Oveready, you can get a Logan that takes a 17500 cell, and with an adapter set, will take AA/14500/CR123/RCR as well. You can get a momentary switch tail for these (but not a true clicky) I believe you can also order the same light from Peak, but not the cell adapters. The Eiger, taking an AAA, can also be had with a momentary (thought not clicky, tailcap.) There is also a straight AA tubed light, but I forget the name. These can be had in single level output models and ones using a QTC pill, which will give you infintely adjustable brightness (well, infinite to the limits of the emitter and drive current, but you get the idea). Peaks aren't fancy, but they are well made, and they are a nice solid chunk of metal in whatever type you choose. They have a nice "refined tool-light" vibe to them, but are a bit classier than most production lights.
I don't have any experience with more expensive/purely custom lights (I consider Malkoffs & Peaks "semi-custom" imeaning, limited production of "standard" models in a small shop with high quality). That said, I've been researching and contemplating a Mac's XM-L EDC, and a Prometheus Alpha (though the later is isn't a pocket-size, but rather, a duty-size light.)
