I have to push the HK91 because it is my favorite rifle. Simple, reliable, accurate, and mean.
The mags are cheap now, I bought 6 factory 20 round mags for $24. The Claw mount allows you to take scopes on and off with no change. The PSG-1 Trigger is nice...but spendy $430 in my last HK price list. I have a Williams Set trigger which lets off at 2 pounds and it was $185 for the trigger job.
The HK91 is my deer hunting rifle. I have a ARMS scope mount and a Leupold 3X9. What I love about a HK is that rain, snow, mud it will never jam...and that is important to me for deer hunting.
FAL is another good choice. Cheap mags, and it is not too spendy $1100 to $1500 for a DSA. I have a DSA 16" carbine and it is a very nice rifle and shoots great. My Father also has a DSA with a 3X9 Trijicon Scope for Deer Hunting.
I have a M1A and I am not a fan. It shoots good and has a good trigger. But it is heavy and really long. I do not like the over size wood stock, with a scope it needs a cheek rest.
I have a slight dislike for the M1A because it did jam on me when I was deer hunting
I don't have a AR-10 yet. I think I am going to get a DPMS LR.308 18" The are well built and cost a lot less then a Armalite AR10.
But trust me the HK 91 is a great deer rifle.