I bought a pair of UA Base 1.0 leggins. They fitted me fine, but there was a problem: every time I crouched down in them (as if on a landing or something when boarding), they would go down. So I returned them.
The reason I bought them in the first place was because the boxers I wore last season kept sliding up my waist and it was a hassle to get them back down again. I just want something that stays where it is! Sometime I just can't win.
...Until now. Compression shorts ($10 from Walmart) + sweat pants for cold days (also $10 from Walmart) = finally, an ultimate base layer that stays in place!
The best part is that on warm slushy days I can just go without the sweat pants.
You save $35. You get removable layer. It stays in place. You get happy face

.
Quite simple, really.