From what I can tell over the past 10 years or so, La Nina produces a trough in the jet stream over the western part of North America, allowing deeper infiltration of arctic air. It produces a ridge in the jet stream over the eastern part of North America, which tends to counter the infiltration of arctic air. El Nino is basically the reverse condition.
I like whatever gives a cold winter here. I love the cold, clean air that comes out of the arctic, and I enjoy snow. Basically I like distinct seasons, and I don't like it when the weather feels wrong for the time of year, like when we have 70 degree weather in January. Yuck.