My favorite bras are any VS demi bras. They give a lot of lift, a nice shape and in my experience last a while. I prefer ones with wider straps, but that's because I am chesty (is that a word?). And there is always bras on sale either on the site or at the store. Oh, another good point about their demi bras, they bra strap doesn't slide up on your back.
Oh I'm constantly trying to figure this one out. I have no clue but would also love to know. So far my daily bra is the BBV at VS. I might break down and buy a Wacoal one though since everyone raves about them.