RE: BEST VARMIT RIFLE IN 223 CALIBER
As driftrider said I would go with a Ruger if I was to buy a rifle for out of the box conditions. If I were to build myself a gun, I would start with a remington and build a MGA Ultra Light. Match Grade Arms is a company here by the house that a friend works at. They build custom rifles and I believe the Ultra Light to be one of the best.
Based on price and possibly upgrade the remington would be cheap compared to a Ruger.
All rifles can be made to perform well but Ruger will probably perform the best out of the box, saying that I have seen some perform pretty shady and need some work.