almost everyone will say convoy C8 xpl-hi v1A
this is because it is an absolutely amazing light for the price. you would be hard pressed to find a flashlight enthusiest who doesnt have atleast 1 c8. Its like the starting point for any collection.
gearbest has the best deals usually on c8s
the astrolux s2 and s3 (14500 and 18650) are awesome lights that are just a little bit pricier
If you want to move above single 18650 size, I like my Thorfire s70s and Convoy L6 but i will warn you, the weight gets old. I hunt at night also (not gators, but deer, frogs, and predators/varmits) and I usually hold my light up at eye level or more often over my head, and doing this with a heavy light (like your maglight) gets old fast.
My final piece of advice, if you arent willing/dont want to fork over the money for good battieries then you should buy a cheaper light. It may not matter with flea market specials lights but with these lights the batteries you use matter. You wouldnt go out and buy a Remington 700 Sendero with a Macmillon stock, mount a Leuopold vx-7 scope on it, and then run Russian surplus steel case ammo through it, would you? Thats the equivalent of sticking ghetto ultrafire 18650s in a good flashlight… Buy you some sony vtc5s or some panasonic NCR18650GAs
and get good charger.