The AK is prolific, simple and reliable, and the semi-auto clones are comparatively cheap by evil black rifle (EBR) standards, but accuracy is not a trait that has ever been associated with them.
In a sense the AK-47 is an excellent comprise but is virtually ALL compromise. It was designed to deliver a large volume of fire and was never intended to be very precise. It is both heavier and less controllable than a AR-15 of similar lenght and weight and is far less accurate. It's real strenghts are peasant proof design and the ability to continue to run even if it never gets cleaned - for years. The loose tolerances and gas piston operation of the AK does offer a reliability advantage in severely dirty conditions, but it is a small advantage compared to all you give up if you do not need to use the rifle under those conditions.
The 7.62mmx39 offers no real stopping power advantage over the 5.56mm and is less effective at ranges under 150-200 meters where the 5.56mm will yaw and fragment while the 7.62x39 tends to bore straight through.
And cheap 7.62X39 ammunition has also dried up, so if you go the AK clone route it makes more sense to get on in .223/5.56mm as they are cheaper to shoot and are a bit more accurate (2.0 to 2.5 MOA compared to 3.5 to 4.0 MOA).
Another one of my favorites is the AR-180. The original AR-180's shoot a bit better and the folding stock is very nice and makes for a very portable weapon with a very usable and efficient 18" barrel - but they are hard to find and in excellent conditon will go for $1200 or so. The current AR-180B is also not bad, especially if you add an Ace folding stock and you can get one for around $700 (before accessories).
------
The M14 was one of my favorites at the time - in part as it did a lot of things well with great stopping power, greatlong range accuracy and surprisingly good snap shooting ability at short range and the 7.62x51 is still my favorite battle rifle caliber. But the FAL/L1A1 handles better and the HK-91/G3 is more accurate in a practical battle rifle configuration. In terms of uber accuracy, the an AR-10 with an A3 style railed reciever and a bull barrel is very tough to beat as 1/2 MOA or better accuracy is common and it will do it all day long. So, like the Ak-47 the M-14 does several things well, but is not at the top of the class in any one of them - except perhaps reliability as with the exception of very tight match grade rifles, you can basically bury them in the sand, shake it off and start shooting.
20 years ago I could never in my wildest dreams imagine myself saying this, but if I could only have one rifle that had to deal with a wide range of tactical situations from 10 to 400 meters, I'd pick some variation of the AR-15 and one of the leading contenders would be a standard M-16A1 clone. It is light and fast handling and (in good condition as opposed to the long in the tooth mostly worn out weapons I was issued) is reliable and capable of excellent accuracy in the 1.25-1.5 MOA range. If the engagement ranges were primarily under 250 meters, I'd choose something very close to the XM-177E2, but with a slightly heavier barrel.
