Ok, I’m an 18650 guy and I want to try a 26650 light. What do you recommend?
For background… this is what I’ve been stocking up on in the 18650 world:
I’m pretty happy with the recommendations in that thread.
The LuckySun P26650-L2 is an excellent light, my review here.
Use promo code GBLUCKYCM and you can get it for $19.73 at GearBest.
I’d go with an X3 from GearBest for $25 - it can take 26650, 18650, or AA.
Trustfire A8 is the most durable and reliable 26650 light that I own, high quality build and is also the smallest 26650 light that I could find.
There are also the MMU-X and MMU-X3 from Foursevens. Neither are particularly cheap. But both are good quality lights. And the user interface is about as simple as it gets: a two mode tailcap twisty with a pushbutton momentary on. Choose the MMU-X if you want throw and the MMU-X3 if you want a floody wall of light. The only real downside of these lights is that they are only available with cool white emitters.
As far as batteries, I think the two best 26650s you can get are the Keeppower IMR 5200s and King Kong 4000s. Either will work well in the aforementioned two lights (or any others you might choose). The King Kongs are said to be slightly better in the current department. But the long runtime that you get with a 5200mAH battery sure is nice. And honestly, I don’t notice bad voltage sag with these batteries.
You can use coupon code LL0205401 to bring it to $25.
If you do go this route and want to use AA, I suggest you also buy the upgraded AA battery carrier for $3.39.
^This
I bought the F13 before finding out that it was a highly recommended light here on BLF. It takes all of 2 minutes to remove next mode memory (pencil mod) and like can said, the rest of the mods are perfect for beginners (like me). I paid $14, but for 10 bucks, it’s a steal. I also just put in an order for the LuckySun P26650-L2 based on Krono’s review.
You don't state a budget but keeping in the spirit if the forum - the most popular are:
Sub $20....
LuckySun 26650-L2 (Gearbest)
Supfire L6 (RMM)
For $20-$30
Check the Warsun (Banggood) or
The Yezl (Gearbest)
For lower $30
Any of the Convoy
$40+
Last is the DQG 26650.
The DQG is nice & small triple. Very cool and worth the $$ but NOT a thrower if that is what you need (I have the 1st gen from ChibiM). I also have the LuckySun 18650 so I would not doubt the 26650's ability or quality (the LuckySun lights seem to be very well built). Next on my shelf is the Supfire L6...nothing fancy but good quality for less than $20 and readily available from a US vendor.
I’m going to say either the Supfire L5 or L6 from RMM at mtnelectronics. I got the L5 to give as a gift but I almost like it too much to give away. It seems to be a nicer version of the Ultrafire F13 mentioned earlier. The LuckySun mentioned also looks similar to these two.
What kind of internals should I swap out? Recommended mod?
Also, holy crap I can’t believe this stuff is this cheap!
Take a look at RMM’s modification options for what you can swap out
Just bought an X3 and a $9 Trustfire 
Followup question, what’s the warmest light available?
If you purchased a Trustfire A8 for $9 please reveal where you purchased it!
I also own the X3, nice light and well made, much larger than the Trustfire A8.
Not necessary but if you wanted to push the Trustfire a little harder since you asked about the internals above and if you can solder you could swap out the emitter with an XM-L2 and replace the driver for a 105c driver, that would be a very straight forward and easy swap. Both can be found at Mtn Electronics.
Yes, interested in one too. What about battery and charger?
Do anyone know where one can get a package deal? on a best bang for the buck light, battery and charger package.
Package deal, just check the $8 box:
http://www.mtnelectronics.com/index.php?route=product/product&path=80&product_id=356