If you want a military-style semiauto, go with a FAL. If you have beaucoup dollars, get an original Belgian, if you want to chop a grand off that, get a new DSA.
If you are on a budget, get one of the IAI all-Imbel guns for about $750.
Mags are under $10 each, spare parts and accessories are plentiful. The gun is incredibly simple to field strip and maintain, very reliable and very ergonomic and fun to shoot.
The only bad thing about the FAL is its rear sight isn't as good as the M1A's. Never bothered me, but if it bothers you you can easily mount a red dot sight or tactical scope on one of the many scope mounts available for the gun.
I also have an M1A and it is a nice gun, but mags are very expensive and the gun is very complicated to disassemble.
Also have had a HK91 since 94, and while it is incredible reliable and durable, it is not as naturally balanced as the other two guns and has a crappy trigger unless you invest in a PSG1 trigger pack. It is also very very expensive if you get an original HK. The only clone gun I would look at is the CETME that AIM Surplus is selling for $500. They also have mags for $18 right now. Not a GREAT gun, but a great buy for that money.
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We are Dyslexia of Borg. Futility is resistant. Your ass will be laminated.