I'm looking for three flashlights right now and I've read this forum diligently all evening before making a post.
I currently have a Romisen RC-F4 which is a decent little light but in hindsight I could probably have done more research before buying. This time I wanted to ask a friendly forum (unlike CPF...) to vet my purchases beforehand!
My first light is going to live in my glove box. My understanding is CR123 batteries are resilient to extreme cold (-40C or below) whereas 18650's are not. If correct, this is the one I've settled on: http://www.dealextreme.com/p/26794
Second light I want to be *bright*. Stupid light up a city block bright. But I'd like it to be a useful bright, not just a really tight spot and no flood. It need not be compact but I don't want anything huge either :). I've narrowed it down to these three lights (potentially)
I am leaning towards the Skyray 3 because it seems like the bloody brightest flashlight under $50.
Third light I want the brightest one I can keep in my pocket. A good flood is more important than raw throw. I'm thinking a single 18650 light. But that's only if anything is significantly brighter than my current RC-F4.
As for your last choice, the 501B with the MCE emitter, I suggest you avoid that. An XM-L emitter puts out more light and is more efficient than an MCE meaning longer runtime. Equally the 502B body is far better than the 501B but no larger. I would recommend this.
However, if you don't mind something slightly bigger but still just about pocketable then almost everyone around here would recommend this light and has one. Its a well driven C8 and really makes superb use of the XM-L emitter.
Both of the above suggestions will be far brighter than your F4.
Moving back to your first CR123A light I'd suggest the Trustfire Z1 instead. Yet again its a favorite around here. Its tiny, superb value and its angle head and clip made it amazingly versatile.
To add options you might like to know that the old ni-cd battery technology is pretty nice for low temperatures. Unusre how primaries (alkies) will do (i suspect lousy).
Ni-cd's a re available for really cheap off ebay still.
Rated 900mAh but probably lower. Energy density leaves a bitter aftertaste but it is still an option for such climate. These are not LSD either but don't selfdischarge so quickly as ni-mh.
Is not the dimension, CR123/18650/14500, that tell you the characteristics but the technology used to build the cell, also if you are right with cr123 are called the disposable litio, rechargeable are rcr123/cr123r/16340 xD
btw i think that AA/14500 flashlight format is better, most of disposable litio are able of run at critical temperature, like cheap energizer ultimate(litio 1,5v) that run at -40C, if you want top performance can buy a disposable li-socl 14500 high capacity and able to run up -55C ... but take care it explode if short cutted like commons unprotected li-ion, sry maybe is just my problem I dislike cr123 batteries coz I wasted a fortune like 10 years ago to make run my photocamera(was 7$ each cr123 xD)
for a budget portable 18650 xml maybe that 504b or uf-2100(have a too floody spot but is very compact and bright, became hot quickly in high)
I agree but the OP didn't request a flooder for his glovebox. If he wants flood you are right. If he wants an emergency glovebox light then I'd go with the Z1 as some emergencies call for at least some throw. With the Z1 you can unscrew the head easily and its becomes a superb floody mule so the Z1 has all angles covered.
Wow, I can't believe how much feedback I've received... what a helpful forum! Thanks guys!
My concern about the KD C8 is I think I'd be quite frustrated with a 5 mode light with no memory function. Scrolling through all those modes just to get a light would be a nuisance.
This is my revised list, thanks to the awesome feedback.
For my glovebox light I'm torn on getting a Trustfire Z1 or just a trusty AA flaslight and putting an Energizer Lithium in it. Those are supposed to be good down to -40C. I can't find many batteries that claim to work at -40C!
For my ultrabright light I'm pretty torn between the DRY, Skyray 3, or Trustfire TR-3T6. The Skyray is more well known, but most people seem to say the TF is just as bright but significantly more reliable. I just can't find much evidence that the DRY is significantly brighter and it costs twice as much. I have small hands so I'm concerned the form factor could be troublesome.
Yeah, the TF 3T6 is more reliable even though its current draw is a little lower than the Skyray (in other word lesser lumen output), but the difference is hardly noticeable by naked eye so it should be fine. I have not heard of any TF 3T6 failure report in this forum yet, so far. The DRY is reliable too, you can find quite many reviews about DRY in this forum, and I am a new DRY owner too, it really rocks!!
If I still remember correctly according to the member 2100, the TF 3T6 has about 1470 OTF lumens on high mode while the DRY has around 2400~2500 OTF lumens on Turbo mode from his measurements. Yeah the DRY is more expensive than the 3T6, anyway it's too bad you have just missed the group buy train that ended last month...
For the third choice, if you buy this one for an easy to carry EDC light, you will smile for years to come and it's small enough to always be on you. I like this XP-G version better than the more expensive XM-L version.
I agree on the Z1 for the glovebox, if you go Ultrafire go 504B, much nicer body. The Skyray (Seraph knock-off) is also a nice P60 light. Shiningbeam S-mini is an easy carry, neutral-tint light for dogwalking, in the backyard, etc. Lots of light from that little 18650 flashlight.
For fun, take a look at the Caveman while you are at Shiningbeam, and also the pocketrocket.
I was considering the Dry light seriously, but two things put me off. One, the CN website is terrible. I couldn't get it to load consistently at all for two days now. Two, it has issues with TF Flame batteries or protected batts in general. I'm not comfortable using unprotected batts, so nope!
For my pocket light I ordered the simple WF-502B T6. I spent way overbudget on the TR-J12 I wanted to save a bit on this one.
I think TR-J12 would worth your overbudget. So do you buy your TR-J12 from DX?
About the DRY I think it should be fine by using protected cells. There are quite a lot of posting here about the DRY, and some members use the new TF 3000mah Flame and turns out just as good if not better. I have order and now waiting for my TF 3000mah Flame to arrive for my DRY, the reason is same as yours, I don't want to stack some unprotected cells together inside the torch, it's too dangerous to hold a grenade in hand
Yeah, I got the TR-J12 from DX. Well, it's ordered at least... knowing DX I'll get it in 6 months. Not to mention they are making me do this anti fraud process involving me sending them copies of my CC, Driver License, etc. That will be my last order from them that's for usre.
I also prefer the TF's form factor. I like knowing my flashlight can be a club if needed, haha.
The end result of joining the Budget Light Forum is always that one spends way over budget but on terrific budget lights. 
