I've shifted away from CR123 primaries, they're not cheap and you can't recharge them. I like guilt free lumens
so I opted for rechargeable lights.
If you decide to do it, listen to the advice on the folks above and do a couple days of research. There are forums out there just for flashlights and you can learn a great deal.
I settled on 18650's as my go to battery form factor. If you decide to go for this route, don't cheap out on the batteries, get good quality ones and avoid lights that run them in series if you can help it. I use protected panasonic 3400mah 18650s.
The two lights that have been out-standing in my experience without breaking the bank are...
1. Zebralight SC600 Mk II (~$70)
As long as you don't need a "tactical" light, this is a pocket rocket. It's about the size of a Surefire 6P / other 2x CR123 lights, and it's incredibly bright. More floody than throw, but still throws due to it's sheer output. Small enough to EDC, walking the dog, etc. I carry it when I know I'm going to be out after dark.
2. Blackshadow Terminator (~$75)
I use this on crash scenes, river rescues and other work that needs what amounts to a portable flood light. Again more floody than throw, but with the incredible output it throws quite well as well, never fails to impress. It would be good to have in a car, or in the house for looking around the property.
Slightly higher than the $50 price point, but IMO a worthy investment. Avoid the inexpensive chinese stuff you see. Some are gems, but you'll have to do a lot of research and check out reviews to find them. I got tired of having lights crap out on me and ended up doing research and spending a little more but have been really happy with them.
Other than that, I do have a streamlight microstream that's always on me. Not too fancy, but simple, small, and just the right amount of light and cheap enough I won't cry if I lose it!
Also this has been one of the most useful websites I've been able to find that compares a lot of the popular brands
http://fonarevka.ru/#Click on the english flag on the upper right. If you press the scene button on the upper right as well, you can compare indoor shots, outdoor shots, longer ranged shots and close up shots. It's a great tool