Well seeing how this thread has been brought back...
Like Targan, I have a deep affection for the L1A1 SLR but because we're talking US weapons here, my favourite US bangstick would be the Stoner 63 system.
I know it's heavy for a rifle but with the extra parts, you can change it to a light MG with different types of ammo feed.
And if you simply must have 7.62mm NATO as well (hey, I certainly would!), there's the Stoner 62 family, the 7.62mm design that the -63 evolved from.
Irrespective of all that and the weight, I've always liked the look of the -63 series.
Stoner 63 in rifle configuration
