For a long time before I went into full bore flashaholism a few months ago, my lights were:
1) household: some generic incan, most recently Mag 3D
2) car: generic plastic 2C in the glove box
3) EDC: Photon II (earlier: Mag Solitaire) on key chain
4) Semi-EDC (in belt pack, not always carried but
always taken when travelling, camping, etc): UKE 2L
The UKE 2L has been a great camping light. I never felt I needed a headlamp or anything brighter than the 2L. Its main drawback was battery expense (123's at $5 or more each), but 123's have gotten much cheaper recently.
Re other lights mentioned above:
1) Minimag/Opalec: I still for the life of me can't figure out why this combo is so popular. It weighs a ton (well, around 5 ounces, anyway 2x as much as the UKE 2L) and costs a bundle (you can get a BB400 module for just a little more than the Opalec). When camping and travelling, every ounce you have to lug around counts, so I was overjoyed to ditch my Minimag for the UKE 2L. Who really cares about 10+ hours of runtime? Why are you going to run a light all night? A few minutes to set up a tent or walk somewhere is generally all I've ever needed from the UKE on any outing. If you really need an all-night light for reading in your tent, try a CMG Infinity for $12 (uses just one AA).
2) Surefire L4: drooool, yes I want one of these, might replace the UKE with it, though I'd be a bit scared of losing it. But I want it just out of flashaholism, I haven't figured a real use for it that the UKE doesn't do just as well.
3) EDC: I supplemented my (green) Photon II with an Arc AAA and love it. I also have a CMG Ultra and that's a real nice light too, though a bit heavy. The coming Arc AA will be lighter.
4) Surefire M6: man that is an awesome light. I doubt I'll ever buy one but it's incredible to try out. Note that it take a half second or so to come up to full brightness, which might matter in some tactical situation. Anyway I can't see myself buying a $300 light just to use on robbers, but YMMV.
5) PM6 with LED mod: a beautiful McGizmo creation as always, but awfully expensive to just leave in your car for occasionally fixing a flat or whatever. I want to upgrade my car light (now a generic 2D) but will probably stay incan, maybe to one of those $13 Dorcy 2L lights if my local Costco gets them sometime, or maybe a PT 40. The upgrade is partly to get more light, partly to switch to a smaller light to make more space in the glove box.
6) Inova 5T: well-made light but seems kind of silly, oversized, overweight, uses two 123's but with half the output of a 1 watt LS light.
My feeling about Luxeon LED lights in general is they're functionally superior to similarly-powered incans, but not by so much as to make them cost effective unless you have special requirements (e.g. caving) or you're a flashaholic (buying the light for its technical niftyness as well as for functionality). We're talking about a $70+ Arc LS vs a $6.50 PT Blast, for example. The Surefire L4 at $120 is a bit more attractive if you need the small size for EDC and the alternative is an E2e ($70-ish), but if you don't mind a slightly larger light, there's the Surefire G2 at under $30, or the Dorcy if you can find it, etc.
For low-powered lights, of course, LED's rule.
Anyway, my low-cost/practical suggestions are:
Keychain light: Arc AAA ($13), the best light of this type. Downscale alternative: $1.00 LED coin cell light from Countycomm.
Pocket light: PT Blast ($6.50 from TTS). Upscale alternative: Arc LS, Surefire E1/KL1
Camping: PT Blast, plus a spare one for backup (three of them with batteries weigh less than a 2AA Minimag).
Upscale alternatives (more brightness): UKE 2L, Surefire E2e or L4.
Robbers: dunno, not my area
Car: PT 40?