Just to be a bit contrary here, though not without reason. I'd go with the Ariska for a very simple reason. Its called K.I.S.S. as in Keep It Simple Stupid. The scope on the Ariska used an etched reticle with windage and drop markings much like that found in modern varmint scope. The action was extremely robust as was remarked upon by none other than P.O. Ackley who's post-war experiments included testing bolt action rifles to destruction.
One other valuable aspect is that the ammo issued for snipers in the field used a fast burning powder in the cartridges. When fired down the 32" barrel there was no flash and little smoke.
The problems were that it was a bit cumbersome (something it shares with the Nagant) and the scope could not be adjusted in the field, a mixed blessing because this also made it somewhat idiot proof.