Originally Posted by Xela
For the bottoms, I use CW-X, 3/4 length. These are pricey, though. They come in basic and insulated. I now have one of each.
I've been a fan of 3/4 length 'long'-johns for years now. They stop right around where my ski socks top out, and don't add any wrinkles to my boot calves. I'll never wear full length ones again. I've been eying the CW-X ones for a few years but they are so pricey. Found a pair on sale last season to try them. They are really nice. Well put together, comfy and warm. I live in CA so I didn't get the extra insulated ones. But they're plenty warm anyway. After my experience, I'll be buying another pair next time I need bottoms.
For tops, I'm loving the light weight merino options as a base layer. Backcountry has their Stoic brand that are often available cheap, Patagonia makes a really nice one, there are a bunch of other brands too. I find they don't get funky smelling (great if you're on a two-day trip and only want one baselayer), wick well and aren't itchy. Most of the time in Tahoe, one of those, plus a poly ski shirt and a shell jacket are all I need. In WI, I'm guessing you might want a bit more insulation than that.