Maybe I can help...
I'm still a rifle newbie. With the exception of a .22 I had years ago, the first long gun I purchased was this past September. It was a Winchester 94 in .30-30. in October I got my first AR, my fist M1, and an M1 Carbine. I've been shooting the bejeezuz out of the last 3 since, and can offer some insights to a new purchaser.
AR: Fun as hell to shoot, and cheap, too. I threw an inexpensive red dot on mine after I got comffortable with the BUIS, and love it to death.
Lever: Fun, but gets tiresome over time. It shoots with a boring reliability, but there's really nothing that exciting about it.
M1 Carbine: A ball to shoot. There's really little more that one can say about it.
M1: People worry about recoil, and the first time I shot it, I *did* come home with a sore shoulder. Then I learned to really pull it in tight and shoot the thing. Since then, it's become my favoritist rifle, and the recoil is something I look forward to, as I know what it's going to do.
Some perceived drawbacks: With the AR, I would not call it a user-friendly shooter. It does not balance well compared to the other 3 rifles. I consider it a "form follows function" firearm, and I personally believe that it was built as a platform with little consideration to the shooter in mind. Though mine weighs half as much as my M1, I get tired shooting it faster.
M1: Can be somewhat expensive to shoot, though there is cheap MilSurp ammo out there. Some of it is corrrosive, and if your read the post about an AR taking a while to clean, they're nothing compared to what you need do after corrosive ammo. But, non-corrosive MilSurp can be found relatively cheaply also. Then there's the weight consideration. 9-1/2 to 11 pounds of rifle can become a bear to hold up at the range over time. Some find it troublesome, some don't. If it starts to get heavy for me over and extended range time, I just switch to the Carbine or AR for a while. That said, it was designed beautifully. It balances extremely well, and that adds considerably to holding it up to your shoulder to shoot for long periods.
Carbine: Fun, fun, fun. Mine's an October 1943 Underwood, and the Carbine owners have almost a religious fervor about them. I do, too, to an extent, inasmuch as I listed the age and make of mine, and bought it specifically because it was a WWII configuration, meaning there's no Korea-era additions to it. They are a gas to shoot, no recoil to speak of, are light, combat-accurate, and .30 Carbine ammo is cheap. However: the cartridge is not particularly powerful in relation to the others, and as such is not going to give you great, shooting match accuracy. It was designed from the ground up as a defensive weapon.
Lever: As I said, it's my least-shot rifle. I bought it because I feel that every long gun owner needs to have at least one lever, and mine is certainly reliable, relatively accurate, and fun to shoot, but it just doesn't blow my skirt up. Also, .30-30 is not the cheapest ammo around. It's far too popular, so the ammo makers don't need to offer great prices on it.
So. Which to buy? I would recomend the M1. AR's will be around a long time, and with the White House secured for the next 4 years, you can always get one, and "tacticalize" it up at your leisure, if that's your wont. You might grow tired of the lever, as did I, but that's a personal call only you can make. The Carbine is a gas, but not as a first rifle: it's a supplement to get afterwards. The M1 is a tangible piece of history, though its availability is slowly, inexorably waning as they're bought up. They are fun to shoot, there's no substitute to that "PING!" as the enbloc clip ejects, and its accuracy out to 400 yards is a given.
Besides, where else can you get "M1 Thumb?"
..Joe
