My K31, which should surprise no one. More accurate than I am by far, and I haven't even bothered handloading with it. I doubt I could come up with a load that could rival GP11 anyway.
Second would be my beater Chinese SKS, which was my first centerfire rifle. The wood is dinged to heck, the bluing is starting to wear away, and it's had some rust issues on the outer-bottom of the magazine because I was a bozo and forgot to oil it after a humid, long day at the range where it contacted my sweaty hands and the dirt for an afternoon. Doesn't shoot any worse than the day I first got it brand new in the cosmoline, and the rifling is still perfect with that nice mirror finish from the chrome lining. They may be heavy for what they are and not exactly the most ergonomic things on earth, but when used within the paramiters of what it was designed for, you really can't beat an SKS.