Love em! I have quite a few in my collection. My favourite is probably the Baldur's Gate 2 CE:
When I was younger I had a lot of these first hand. I remember throwing them all out (shelves upon shelves...) thinking I wouldn't need them again. It's taken me ages to source most of these.
What I like best is the art, the size, and the things that are largely functional. Guides, maps, instructions and so on. It's all great for the game. There's too much gimmicky crap these days. I also love backing Kickstarters with big boxes, this is basically the only way to get them for new games these days.
If only I could find boxes for all the games I had played back then. But most people charge stupid amounts for them :/