The people's cartridge, stocked deep: bulk .22 LR bricks for plinking days, CCI Mini-Mags and Standard Velocity for reliability and accuracy work, subsonics for quiet rifles and match loads for rimfire competition.
Semi-auto rimfires can be picky - if your 10/22 or Mark IV stutters on bulk ammo, a step up to Mini-Mags usually cures it. Cheap enough to test, cheap enough to shoot every week.