As usual, I’m gonna ask first before anything else… whaddya gonna do with it?
Grubble through dark basements/attics? Walk the dog at night? Spot owls in trees? Etc. Ie, close-in work where you want something floody, or farther-out spotting where you’d want a thrower?
For a general purpose light, I’d recommend the Zanflare F1 or the Nitefox UT20, both of which have built-in charging, aren’t overly high-strung and will let you use even laptop pulls (as I often do), and are nice easy to carry tubelights.
I got 4-5 F1s, and just got a UT20. I’m really impressed with both as far as build-quality.
The F1 never comes as a kit, so you’ll have to buy a separate cell for it. You can, if you’re willing to wait, pick up a F1 for 20bux on a flash sale if/when GB offers it, else it’ll be priced something obscenely higher if not (like, double, 40bux).
The UT20 can be had through Amazon for 23bux currently without a cell. They (Nitefox) have a decent 2600mAH cell with protection and built-in charger(!!), too, for 10bux. That’s actually cheaper than getting the kit (light + regular cell). The cell’s pretty good, ’though it’s 5A max drain, and clocked in over spec (something like 2610mAH for a 2600mAH-rating). The light doesn’t draw more’n 3A or so, so it’s plenty.
For a “starter kit” of an 18650 light, either one of these is perfect.
If you’re not emotionally attached to a built-in charger, there are so many other lights out there, but they’d of course require a separate charger. Get a LiitoKala 100 or 202 and be done with it. Under 10bux for sure.
And look, later on, you can get bigger, beefier, even almighty chargers (seriously!).
But as far as 18650 lights, the S2+ is an old standby, and you can substitute TIR lenses from spot to flood. Or use it as-is with its reflector. Thorfire and Sofirn also have a nice assortment. My SF31WW (yes, warm-white!) is a keeper, albeit discontinued. Then there are those lights that take drop-in modules.
While the C8 is highly regarded, especially the C8F, C8s in general are throwers, not suited too well for close-in work. Certainly not for, say, lighting up the ground in front of you on a dark trail. You’d be blinded by the small but intense hotspot, whereas the spill will be almost useless after you’re so blinded. Best to get a nice flooder, like an S2+ with a 60° TIR lens swapped in.
Like I said, it depends what you wanna do with it.