+1 on the Microstream. I own two. I wear one around my neck every single day. I use it almost every day as well. The new models IMO are the best, as they have a pocket clip that's bi-directional, you can clip it onto the bill of a hat and use it as a head light and comes with a decent neck lanyard. It's light and uses 1 AAA. It does use that AAA quite quickly though, rated at 1.5 hrs, I've never tested that, but I'd say it's about right for 48 lumens. I have an older Stylus pro as well, thing is an awesome light too, recently they doubled the brightness on them as they did with the micro stream. Both are great, but the Stylus Pro uses 2 AAA batteries and is obviously twice the length. Other than that, they look exactly the same! I'd recommend them both.
The Maglite Solitaire and Mini mag are excellent incandescent counterparts I might add, if you don't like LED. But as Jerry pointed out, the entire Maglite line has LED conversion as well. Those conversions are pretty solid, and work quite well too. I actually keep a Mini-Mag in my glove box, along with two full sized Mags at either end of the BOV. When you factor in the LED conversions, however, I find the price point of both the Streamlights and Maglites the same(for Pen sized lights). So it's a matter of style and brand preference for you. Although I will say that the Mag's being a tad older have a higher number of dedicated accessories via Nite Ize.
Good luck brother, happy hunting!