What's the best gun for deer hunting

It depends on your skill and the terrain where you hunt.

If you hunt primarily in densely wooded areas, the classic .30-30 lever action is generally the leader. It's compact, quick to shoulder, has a quick follow-up shot capacity, and is best in the 20-75 yard envelope.

If you hunt in open areas (prairie) areas with light tree density, you can go for a bigger caliber with longer range. The aforementioned .308 is always a good choice, but I agree that it's overkill for deer.

My choices:

.30-30 levergun (Marlin, Winchester)
.243 Winchester bolt action (Tons of makers)
.270 Remington bolt action (Tons of makers)
7.62mmx39mm (SKS)

A water pistol!

I have used a Marlin 30/30 for years--and have always had good luck with it. My husband just recently bought me a .243 youth model which is more suited weight and length for me; I really like it also. I haven't got to actually hunt with it, just practiced while sighting it in. Both of my boys and my husband hunt with Winchester 30/06.

a paint ball gun just kidding i hunt with a sako 270

I think it depends on the terrain, distance from prey, build of the hunter and personal preference. You might also want to consider any other game you would want to use the rifle for. Some rifles will be fine for deer but not adequate for elk.
I know that many times hunters will use pistols of sufficient caliber to hunt, but this is not practical and a rifle is easier to aim and more true in striking the target.
My family members currently do a lot of archery hunting. It is more of a challenge and requires more skill. A few others have gone with black powder in the past. While they had a good time, they didn't stick with it for actual hunting for long.

Any decent bolt action in .30 caliber is good for deer. More refined hunting rifles are available for skilled hunters, who will prefer a .243 or .270. Semi-autos are generally not desireable. Also, a 12 ga. shotgun with sabot slugs or 00 buck will suffice, but this is a much closer-range weapon which requires a stand or blind to use effectively.

A bolt action rifle with a 5 round magazine or a pump shotgun:

Either a .308 or a shotgun with slugs or sabots. Shotguns with buckshot aren't good unless they're a) 000 or 00, and b) steel shot - you don't want grandpa breaking his bridge on a piece of venison.

The .308 is generally the popular round (7.62 x 51mm), although it tends to through-and-through with unskilled shooters, causing them to chase a long bloody trail (Northwoods 'rule') to get their kill. The slugs and sabots have serious knockdown power anywhere on the body of the deer but are really only effective to 50 meters. A .338 mitigates and is the cross of the slug and .308, because it blows a hole the size of a basketball in an animal like a deer.

Disclaimer:
I do not hunt with firearms because I wouldn't eat what I kill nor do I consider it a 'sport'; I am an expert shooting paper and know many hunters.

It depends on your skill. if you have good aim you could use 1 243 or 270. If you have bad aim use a 30-30 30-06 or a 308.

A fully-automatic UZI.

mossberg 500 12 gauge with $3 dollar a box winchester
slug's 1oz , just finished michigan's 2009 shotgun season with 2 buck's and 1 doe ,

I started out with a rifled barrel and federal premium
sabot's,that got expensive real quick $15 to $20 per box, since i had issue's w/ scope i went thru a few of these and missed a few nice deer,
so i put my smooth bore barrel with iron sight back on ,and shot the first BUCK the next day a nice 7 point, I think i'll stick with winchester slug's 60 cent's a shot,and my good OLD mossberg 500

.270 bolt acton or 30/6

i have used a mossberg 100 atr in .270 win for the last 2 seasons and every deer i have shot with it has dropped. i reccomend this rifle and caliber for any thing you are hunting

depending on the terrain that you will be hunting it varies. i use a 270-win when i am hunting in brush or open areas.

If I could have only one gun it would probably be a bolt action .308
They are generally surgically accurate and you can use heavier bullets for bigger game or lighter bullets for smaller game like deer.
For all around hunting the 165 grain JSP is about the best bullet weight I have found.

I would use a 35mm with a long lens. That way you can shoot the same deer tomorrow. With a good 35 you don't have to worry about field dressing or carrying him out to the truck. Also most states don't have a limit on the number you can take with a 35mm. Be carefull! There are people out there with guns who shouldn't be.

I would use a .243 winchester, good range, good round. But some jurisdictions restrict what can be used to hunt deer. In mine, shotguns, muzzle loaders, and handguns rounds are the only means allowed for hunting deer. In this case I prefer a 12ga rifled shotgun shooting sabot rounds, or either a .44 mag lever or pistol.

dont usually tend to go for a shotgun because of unnesesary recoil; a standard air rifle with 7.5 zoom should raise a few deer eyebrows

winchester 30-30

ithaca 66 20 guage with remmington super sluggers

The one you can hit with. Of course you need to use a gun with a minimum amount of power. But power, while important, won't kill anything unless the bullet hits the target. So, experiment. Do a lot of reading. Go to the local rifle range and ask some people who are shooting bolt actions. I suggest asking shooters of bolt actions because they may know something about lever guns but shooters of lever guns are less likely to know about bolt guns. Just my observation. As as been pointed out, much depends on the country where you hunt. Close-in shooting, less than 100 yards, calls for a different gun from country that is open and sparsly covered. If you have to shoot out to 200 yards, you need more power. But check with actual shooters at the range. That's the best approach.

30.06

An accurate one. I use a 30/30, 30/06, 270, and a 7mm Rem Mag...Some are over kill and some are just right; depends on terrain and tactics being used. The bottom line is all the rifles I own put bullets right where the cross hairs are. If you are a proficient shot I believe a 30/30 is all that is needed out to 250yrds. "Zen and the art of bullet placement in spite of excellerated heart rate" :-)