Other question, different answer. In my car I keep a Frankenstein thrower. When working on the benchgrinder I stick an SS Enogear on my cap. Working in the attic, or under the floor, requires a Wurkkos H15. A totally different (blue) light when I have to look for a toy my dog lost in the garden. Walking the dog a Fenix CL05 lip light on her harnass while I carry a Thorfire VG10 in my pocket. That is to say: it looks like a VG10 on the outside. Not on the inside. My favorite EDC.
For this new question variation I would also go with my Zebralight SC64w HI. The perfect light does not exist, but my favorite one does for sure.
For favoritism the one I carry daily must be the answer. I made it around 7 years ago and have carried it virtually every day. A quad LH351D in Titanium and copper.
3 Thanks
Sure, but there’s something in for you:
A Quadrupel E3S 
Yes, the most valuable lights are those with a story.
2 Thanks
Emisar D4v2
1 Thank
Noctigon KR4 w/ 219B sw45k LEDs (or dedomed 519A 5700K would probably be good too). It’s like a FW3A, but with some important upgrades:
- Easy to reflash firmware
- RGB aux LEDs
- More powerful MCU (smoother ramp, and fits more features)
- Better clip
- Better button
- Better build quality
- Nice rosy sw45k tint, without having to mod it
- Choice of drivers with very stable, consistent output and no PWM:
- Linear driver (cheaper, brighter turbo, lower moon mode)
- Boost driver (longer runtime, less heat)
Plus, of course, a tail e-switch for “cigar grip” style use. That’s the main reason for using a KR4 instead of a D4 or D4K.
This is the light I use the most. Mine is titanium, but an aluminum model would cost less and weigh less, which are both good things.
1 Thank
TK goes Ti, I like it! 
Favourite flashlight? Has to be these two:
Emisar D4V2 has 4x SST-20 4000K FA3 bin, ever so slightly rosy on all levels.
ZebraLight is much cooler at 5000K but pretty much neutral, really won the tint lottery with this one (for a ZL).
Super smooth flood thanks to the frosted lens.
Not an expensive or rare light, but my favorite is the Convoy S21D (specifically the 8A 519A 4500K 60-degree version. I have 5 of them.) Simply a magical floodlight just small enough to fit in a pants pocket.
4 Thanks
My answer is difficult for me to formulate. The problem is that I have so many lights. I typically get a new light, then use it to check it out. If I like it, I stay with it. Which means previous “favorites”, get shuffled out of the lineup.
There is also the fact that I have certain lights for specific situations. So a favorite for field work is not usually something I want in my pocket all of the time.
So, if I define “favorite” as the one(s) I currently use the most, It would have to be the S21D mentioned above and my TS10 (which I carry everyday all day). Thanks @nicodimus22 for reminding me of S21D.
1 Thank
Emisar dt8k small enough to carry in a pocket but very bright flooder. Good head beef and cooling fins and with the boos driver, 519a led, tons of light for a good amount of time.
Never a dull moment around here.
1 Thank
We have it every year, here is the most recent:
2 Thanks
The smaller one looks cute.
My favorite practical light is probably the Emisar D4K in my pocket, with Dedome 519a 5700k emitters. It is the perfect size for EDC, and the beam cct/tint is beautiful, as well as having great UI.
Favorite “for fun” light is either the Acebeam X75 for its extreme brightness, or DT8 W2 with 18350 short tube, it is incredibly bright for its size.
1 Thank
3 Thanks
It looks pretty cool! LEPs make a fidget torch a bit funner though. 
Is this the LED version! Nice colors!
Bingo.
1 Thank
Noctigon DM1.12 with 519A (but no SBT90.2), or Mateminco FW1.