An M-1 Garand wouldn't be a bad idea. As far as ruggedness and durability go, it is hard to beat a Garand.
Here are some others.
The Springfield Arms M-1A, the semi-auto version of the M-14 (although the M-14 wouldn't be too bad of an idea either), which has seen some action in Iraq and Afghanistan as a sniper rifle, gives you the ability to reach out and touch someone.
The Galil Golani, named after the IDF's famed Golani Brigade, is produced in the US by Century Arms and comes with a side-folding stock and a 35-round magazine.