I hate flashlights. They always make like a ring of light with a dark spot in the middle. And the middle is usually what you want to see. Do they make them that don’t do that?
These are the best flashlights I’v eever seen. I’ve never owned one so i can’t attest to batterly life, But a few of my friends have them, and they are unbelievably BRIGHT and SMOOTH with out the irregularities you are talking about.
They also ain’t cheap, but they’ll bury you with it, so if you use a flashlight often enough it might be worth it.
CJ
Yes, my dear, they do make flashlights that don’t have that.
You want to look for a flashlight with LED bulbs. My new headlamp has LEDs and it rocks! http://www.petzl.com/petzl/publicFamille?id=LAMP&rub=sport#TIKKA (click on TIKKA)
Opal, you can get LED flashlights at the C. Crane Company. Never had one myself, but if Green Bean says they’re good, well there you go. They’re pricy, but might be worth it. They’ve got crank flashlights, too; in case you run out of batteries. 
I have a photon fusion LED combo headlamp/flashlight (light detaches from the headband) that produces an even light. There are no rings at all nad no darkspots. THe light basically follows the bell curve being very bright in the middle (and fairly large) and gradually tapering off all sides.
ALso the LED’s last something like 5 hours on brightest (with 3 AA alkilines) and something like 3 days on medium w/ rechargable batts.
Most LED lights will not allow such brightness and offer longer battery life but this one has a full brightness - just somethign to look out for.
Um, the circle is produced if the light source and the parabolic reflector are not adjusted correctly and the beam diverges. Most flashlights (except the really cheap ones) allow for the adjustment of the position of the lightbulb with respect to the reflector and you can make the beam parallel or even slightly convergent. If you understand this you can adjust the beam to your liking.
Sailor: the only flashlight I’ve ever had that lets you adjust that is my tiny little finger-size mag light, and to get the circle to go away, you have to turn it so much that the battery chamber is practically open 
k2dave: photo makes full size flashlights? cool! I have one of the little keychain ones and I love it…
Opalcat Here a pict of one
Thought you can find it for about $25 less but still expensive.
Basically the text ad is true - it really is a very good light and very versitile.
The downsides that they don’t mention are:
1 the battery ‘clip’ looks somewhat flimsy and you want to be careful replaceing the batts.
2 you have 2 buttons - one is ultrabright on/off which is no prob. The 2nd cycles between high/med/low/fast strobe (incase you want to get sick I guess)/ slow strobe/ SOS/ 1 minute full bright. Which means if you want to go from med to high you must cycle through all the above - it is also a on off button. I would much rather just have high/med/low and ditch the blinking modes.
3 (nah - I couldn’t) You don’t want to loose this flashlight (Like I did - Ouch $$$)
Opal, all Maglites, large and small aloow that adjustment “as you go”. Other flashlights allow a more permanent adjustment in that the lightbulb has a counternut so it does not have to be screwed in all the way. You position the lightbulb in the position that works and then you secure it in that position with the nut.
I have here a cheap flashlight with a reflector diameter of about 3" and when well adjusted the beam will illuminate something even at 150 yards or more.
What you need is a bright lightbulb and a good reflector in the right position. that’s all.
Yeah, I use a big-ass Maglite (well, 2 d-cell size, at any rate) and I can adjust the beam. Works pretty well.
As others have pointed out, there are major gonzo expensive lights that are better, but as someone who uses a flashlight every day in professional life, I find the Maglite is just fine for what I want it for. YMMV