Honestly if we're talking about the rifle that is most reliable, rugged(durable) and accurate at the same time - in other words, it has to have all three of those, as opposed to sacrificing one for the other - I would pick the G3. The much-maligned and underrated G3 manages to be insanely durable and insanely accurate at the same time. The FAL might edge it out IF it had better sights, but as-is, in stock configuration, I think the G3 is the winner if we're looking for a rifle that has extreme reliability, extreme durability, and extreme accuracy all in one package.
The downsides of the G3 are that it's heavy, and is not very ergonomic. It has a heavy charging handle that's far forward, thumb safety that's hard to operate without adjusting the grip, and there is the notorious fluted chamber that mangles the shell casings and flings them the length of a football field. It lacks a bolt hold open on the last shot, and it would be helped by a bolt forward assist. All of this might be true.
BUT - it's rock-solid reliable, with the durability of the AK, and it's absurdly simple to take apart. It doesn't have a gas system to worry about fouling or failure to cycle. And it has very good sights and a slightly higher degree of accuracy than the FAL.
For bolt actions I would pick the Finnish Mosin.