I have four Ruger MK II's (one is a MK II era 22/45). They are all very accurate, and reliable. I've modded one, 5.5 inch bull barrel, with some Volquartsen trigger parts, and it works great, not that the stock triggers on mine are bad at all.
That being said, the Browning Buckmark is the other one I'd consider if buying another .22 pistol.
Either the Ruger or Browning will serve you well.