I think you and mrheosuper are in agreement. I agree as well, 14500 is my first choice for EDC because it is slimmer than the others. But I also like 18350 and 16340 size lights.
What is the light on the left?
Where’s the button for AAA? 
@ DavidEF
The one in the middle is a 14500 light, a DQG Slim Ti 
So I wanted to show that some AAA lights , such as the Olight I3T EOS (right) and a generic 2€ Zoomie from a Chinese store, are bigger (although a bit “slimmer”) than the DQG
@ Agro
It is cheappo light, a zoomie one ! Bought it in chinese store as I wanted to mod it but…I’ll let it go! 1 mode, put an XPG2 inside only and I call it a go 
EDIT: Stooopid me, only now I notice that the “,” (comma) was indicating the answer and not an enumeration :person_facepalming:
I get what you say now, DavidEF
DQG Slim! Ah, I missed the joke! 
AAA.
I also like AA but consider that medium sized.
I don’t normally need big lumens from smaller lights. So I prefer nimh for availability, cost, and stability.
x2
I had a dream about an AAA size RRT-01 with LVP, then I woke up to my Phat TCR-1 with an unprotected 18350…
The perfect light is a combination of features, none of which exist in any one model.
Same as Women.
I like to have more than one.
.
Does Size Matter?
from shortest to longest:
short and skinny: ET 16340 2.9”
longer and fatter: RRT-01 18350 3.2”
long and skinny: ET AA 3.4”
Four of my favorite small cell pocket lights.
LAN Mokume Gane XP-L HI 5000K, 14500, Electronic Tail Switch.
FourSevens Atom XHP50.2 3v 2A, 16340, Reverse Clicky Tail Switch.
CRX CuTi Zoomie KW CSLNM1.TG, 18350, Forward Clicky Switch.
CRX Rotary XP-L-HI 5000K, 18350, Rotary Lighted Tail Switch.
Definitely 14500
14500 for the same reason as everyone else - slim. I would’ve thought 18350 got more votes for drain rate and capacity but there you go…
14500 lights are my choice. I like the slim profile.
14500. Because its slim and the ability to swap out with a AA.
For the last few years, it’s been the EagleTac 2014 D-25 25 ti. clickly.
Chris
Ah, I thought they were all AAs.
I am looking for a really slim AA zoomie and this looked like one.
Yep as a clicky the eagle tac and the xeno es1 are the same size (small and thin ) Eagle tac takes either battery and the xeno only wants the AA..The old Eastwood / blf light modded with a nichia is still a very small nifty lil clicky.
In a twisty the old Thrunite T-10 and the jet beam are nice and small too .
Still love a plain old nichia 219B Lumintop tool at only 20 grams with a battery it's often found clipped to my collar .
Nice part of having lots of lights is they are what they are and if weight is an issue than leave it on the shelf . I still love some AA lights that are bigger than some 18650 lights ....just not all the time .
Don't need to bring a gun to a knife fight
I prefer the 14500 format because most of them can run also with regular AA battery.
i would say 16340 for me then, seems to be my fav i would have to vote.
Among these three, 18350 for sure. For me, capacity is everything, and it’s one reason why I have two 16340 torches and hate both of them.
But for real, I won’t go below 18650 and don’t plan to change that opinion anytime soon.
I agree.
18350 for capacity, but I don't even use those because 18650 cells have the most capacity per volume.
(Except for maybe 21700 cells.)