The brightest light for backpacking the SHT

You'll probably want to balance brightness with battery life if you care about weight. The brightest light I usually carry is Black Diamond Spot. When I really want to cut grams, I carry a Petzl Zipka.

Don't have anything specific for the SHT, but all I used to carry was a single AAA battery flashlight, but that light is now relegated to "around the house" use unless I forget and leave one of the dozen or so I own in a pack recess (Gerber Sonic, probably no longer made). It definitely is NOT "bright".

If I was going to hike at night, and sometimes if I was actually going to read (a paper book, not a self-lit Kindle or other device), I'd take a headlamp (used to carry an early BD Moonlight, but now I have a half dozen BD Storms floating around here and there and in various packs/shelves/etc.).

Somewhere I read that AA batteries were "more efficient" in terms of power/longevity based on weight over AAA ones, so I bought a small single AA flashlight, and that's pretty much what I use (or intend to use - haven't been out often enough lately). The one I got is a (wait a sec: it's right here in my tiny "hydration pack" for nightly hikes - the wife needs a lot of light; used to carry my old BD Storm that provided enough light (100 lumens) to keep her from tripping on roots and uneven sidewalks, but the flashlight is lighter and smaller and I carry it "just in case" we're out late - yeah, it's a Fenix E12), though I suppose there are better and worse lights out there. Its lighting goes:

High - 130 Lumens (1 hour 30 minutes)
Mid - 50 Lumens (6 hours 30 minutes)
Low - 8 Lumens (40 hours)

and starts on "Low" when turned on. Tapping the tail switch cycles through "Mid" and "High" and then back to "Low". I prefer this arrangement - it saves battery unless you actually need it. You might want something brighter than this, but I find the "High" setting to be very bright. "Very bright" eats more battery, as you can see, so you might need to carry something a lot larger.

The E12 runs about $25, though there are probably sales now and again, so it won't break the bank.

I'm sure there are many other like it. There are definitely brighter ones, but I personally don't need a lot of light. I can deal with 8 lumens most times, and 50 is about all I ever need, so the main beam on my BD Storm headlamp is pretty much wasted.

Additional note: Be aware that, if you WEAR a headlamp, you may experience a "flattened vision" syndrome (which I do) because you can't see shadow with a light close to your eye (though a headlamp is absolutely a must for, say, searching for wolf spiders - the light from their eyes only gets reflected back to your eye if the light source is close to your eyes. One night I found a momma spider with hundreds of babies on her back. The group looked like a large sparkling diamond moving through the grass. Sadly I could not get a picture). This is the very reason I bought the flashlight (except for night hiking, when I might need my hands) - because I found that, most times, I was wrapping the headband around my upper arm so I'd get shadow. If I travel over uneven ground, a headlamp can be downright treacherous, at least for me. YMMV

I also carry a Fenix E12, it is wonderful, might not be enough light for you, but extremely bright for its size. My headlamp of choice these days is a Zebralight H52fw, also a single AA light with a lot of brightness for its size, and quite a bit of flexibility in terms of output. The w indicates a warm, rather than cool white light, which I find more pleasant around camp, and the f indicates a floodlight, rather than a more tightly focused spotlight. If your eyesight is really poor, you might prefer a brighter, more tightly focused beam. If I were getting a new headlamp today, it would probably be a Petzl Tikka RXP. There are tons of good options out there, your best bet might be just to stop by an REI or other reputable outdoor retailer and describe to them in more detail what it is that you need. If you want to be overloaded with tons of information, check out the candlepower forum: www.candlepowerforums.com/vb/content.php . You could also do a forum search at backpackinglight.com .

What TDale said. Plus the red doesn't get on everyone else's nerves at night.