Awesome stuff! My favourites:
AAA: Solarforce L2i (T5 5C1 drop-in), Led Lenser T7
AA: Cyclone C88 (T6 3C), TrustFire Z8 (if all 14500’s are allowed here)
18650: Zebralight SC600, Solarforce L2T w/ A001 head, B6 Bezel, S11 switch (T6 3C drop-in)
CR123: N/A
Other: UltraFire HD2010 (T6 3C), UltraOK A105T6 (T6 3C)
AAA: N/A
AA: Ultrafire C3 Stainless Steel
18650: HD2010
CR123: N/A
Other: 445nm 2+Watt lasers! 
Thanks!
AAA: All my AAA light are rubbish
AA: Balder SE-1XML and Nitecore EZ XP-G (Reserve Trustfire R5-A3 and Jetbeam BA10)
18650: TK35 Clone (Love the design) and SKYRAY KING
(I will get the King some day, I was one of the first to spot this as I mocked the DRY)
CR123: SKYRAY T6 S3 (A Beauty), Ultrafire MCU C7 (My second 16340 light)
Other: N/A
I do really love all my lights, would love to add the Eagletac ss
AAA: DQG Tiny ii, Thrunite Ti
AA: ITP A2, Xeno E03
18650: HD2010, Balder BD-2
CR123: N/A
Other: Maglite 2D LED
AAA: DQG II, Thrunite Ti
AA: Zebralight SC52w, Xeno E03 NW
18650: Zebralight SC600, Sunwayman T20CS
CR123: HDS EDC Rotary
AAA: DQG Tiny II NW, Thrunite Ti (3 LM low)
AA: Jetbeam PA40, Hugsby P31
18650: XinTD SC-82 V3 NW "C8-style", Shiningbeam S-Mini with clip
CR123: Romisen RC-N3 (multi-config flashlight, also takes 2AAs)
AAA E09
AA Stainless steel C3, Balder SE-1 XML
CR123 Aurora SH-034, Triangular Mr.Lite
18650 Spark ST6 460NW, SkyRay King
Other VaraPower 2000 (3D Mag host with 4 Cs)
AAA: ITP A3 Ti, Solarforce L2i
AA: SWM M10A, ET D25A clicky
18650: SF L2
CR123: BLF Mini, ultrafire 501A UV.
Looking forward to this ET D25A Ti!!! 
AAA: Peak Eiger QTC Hi CRI, generic Cree 3xAAA zoomie
AA: Zebralight SC80W, Crelant V11A
18650: XinTD XML C8 NW, Jacob A60
CR123: Crelant V31A NW, Trustfire BLF Mini
Other: button cell eGear Pico light, button cell Streamlight nano
AAA: DQG III Ti NW, Thrunite Ti
AA: Balder SE-1 XM-L NW, JetBEAM PA 40
18650: Blackshadow Darth NW, XinTD C8 v3 NW
CR123: BLF MINI, LumaPower D-mini (modded with Nichia 219)
Other: Roche F22 NW, Trustfire J12
AAA: Ultraok 3xaaa, itp a3
AA: tf r5-a3, Eagletac P10A
18650: Skyray King, Armytek Predator
CR123: BLF MINI, Nitecore EC1
Other: 2 D Mag
AAA: Kriesler approved Tank007 E09. x2.
AA: 4Sevens AA2 Quark, Klarus p2A.
18650: Fenix TK41, Klarus XT20.
CR123: Solarforce. with high volt dropin.
Others : piggy light from DX
AAA: Maratac Cu rev2, Terralux Lightstar 80
AA: Xeno e03, Sipik 68
18650: Solarforce L2p, Trustfire TR3T6
CR123: Solarforce L2m, Smallsun ZY-C1
C: Duracell Daylight 2C
Recommended today (tomorrow, who knows?)
AAA: Bronte Ra01, Fenix LD01
AA: Nitecore EA1, Eagletac D25A clicky
cr123a: Nitecore MT1C
18650: N/A
Other: N/A
aaa trunite ti
aa trunite t10
18650 uniquefire uf-v3, smallsun zy-t08
other, 26650 keygos m10 hd2010.
AAA: Ti
AA: Solarforce L2R, Fenix LD20
18650: Custom triple XM-L maglite, Solarforce L2P
CR123: I hate them
Other: N/A
Thanks!!!
AAA: Fenix E01, Old Dorcy
AA: Quark AA2 Turbo (great 2xAA light)
18650: none yet
CR123: none yet
Other: Remington Hat Light (althought i’m not that fond of it)
(Obviously my collection, is young, thin)
BTW, I’d definitely have the PA40 on there if I still had it :(. It’s a great light period!
AAA: Thrunite Ti (0.04 lumen firefly), Thrunite Ti (3 lumen low)
AA: DQG AA, Thrunite T10
18650: N/A … yet …
CR123: N/A
Other: Fauxton, Rayovac Rougneck 2D (Only “other” lights I own)
AAA: 4Sevens Preon2 High CRI, Fenix LD01
AA: Quark “X” AA², Zebralight H501w
18650: ZebraLight SC600w, Dereelight DBS-T WW
CR123: none
Other:
D: Fenix TK70, Rayovac Sportsman Xtreme 300-Lumen LED Lantern
Nice topic. Thanks for the giveaway.
Why does it matter?