Best or worst, I cannot say, but some worthwhile mentions:
Xenoblade Chronicles 2 NA CE (Nintendo Switch) - It comes with a full size, hard back artbook which you don't see in many CEs of late, a proper appropriately sized steelbook case and a soundtrack CD in a digipak. This ticks all the boxes for me. Perhaps could have been made better by haveing a full OST instead of a Sound selection, but I thought it was a brilliant CE for the $100 pricetag. The PAL version was nice too, but the hardback artbook definitely swung it for me towards the NA version. You did however get a standard game case with the PAL version, which for some is also considered a bonus.
Some people also say that the PAL edition box was the "premium" box, but I thought it felt flimsy for how it looks. Guess it's all matter of individual taste and opinion. Was still very reasonably priced at £79.99.
Zelda BOTW Masters Edition (Nintendo Switch) - An example of a big, fancy CE to start off a new platform with the console's flagship title. Contents were high quality items. Comes with a nice carry case to protect your new console, based on an item straight from the game world (who can complain about practicale items?), a sound selection CD, coin (I love coins
), World Map, a copy of the game and a figure to display. What better than a battle scarred Master Sword in the pedestal. Plus I don't think this was overly expensive either.
More to come when I think of them. Those are the first 2 which come to mind immediately for me.
I don't have a worst yet... ;P