It depends on how you apply the qualifier of "for the buck".
The best rifle is a real FN-FAL, but so few were imported that prices are very high, so they are the best rifle, but at a price. First you have to find one, & that alone can be a problem as collectors aren't parting with their "G series" examples easily.
If the low buck is the driving force than a Century. Yes a Century arms FAL. They have a terrible reputation, but there are some very good Century built FALs out there.
So it comes down to pay a premium price $8,000.00 or so for a real, actual "Fabrique National Fusil Automatique Leger", or a good (& you have to cherry pick to get one.) CAI/CIA for about $750.00 ~ $800.00. Splitting the difference is DSA's offering, somewhere round the $1200.00 ~1800.00 range, current production, decent quality, but currently hampered by switching to home made components & with an iffy customer service reputation as well.