On vacation, and travel more generally, I usually nowadays take my Peak Logan 17500/AA.
Basically I like having access to cheap AA's and not having to depend on finding 123's when traveling. I take a couple of Li-Ions so I can get a quick 300 lumens on max if needed, and a couple of Lithium AA's for long runtimes and low weight at more "normal" yet still strong lumen output levels. If weight is an issue, I will just leave the Li-Ions behind.
The peak has the QTC so you can continuously adjust the light level (though with some coarseness in the levels), so you have access to very low levels of light as well.
For kicks I sometimes take a red LED head, which can be nice to have inside theaters, music halls, cinemas, and the like. No-one has yet complained about me using a red light on low (well, except once, and that was in a cinema in good-old US of A! where some kid from the cleanup crew hassled me about it even though I used it AFTER the movie had finished to check around my seating area in case I dropped any of my belongings, where this country is going sometimes I have no idea).
The whole package is quite light and doesn't take much space.
Occasionally I have taken one of my Glo-Toob's with me, as a signal and to help me locate my own car in unfamiliar surroundings (leave it on strobing at some low frequency, or maybe just on on a 25% level, inside your car, you'll find it super fast) or to mark my pack.
Depending on what I might be doing on vacation, I will sometimes take a second, more substantial and waterproof, flashlight, either for outdoors use or to have around the beach. That would be the Elzetta, with a Malkoff M60L drop-in, for max-throw, super solid construction strength, and excellent runtime.
