One of the versions of the first Golden Axe had this amazing box art

the infamous Game Over cover (uncensored) -
https://www.mobygames.com/images/covers/l/58767-game-over-zx-spectrum-front-cover.jpg

Anyway, here is some I like :

Agony (the good 1992 game...) - https://upload.wikimedia.org/wikipedia/en/7/70/Agony_Coverart.jpg

Telltale's The Waking Dead - https://pm1.narvii.com/6255/f3d14adabfc5c60f9b18a99c662654b87c697160_hq.jpg

Bioshaock Infinite - https://pm1.narvii.com/6255/d9c0a3acae82b197eda302f3e3c64986c4e602e5_hq.jpg

Kingdom Hearts - http://covers.box.sk/newsimg/dvdmov/max1357286878-frontback-cover.jpg


edit -and add to the list any game by the bitmap brothers. for example:

The Chaos Engine: https://i.pinimg.com/originals/98/49/06/98490662af1f9dab633799a128bd6d38.jpg
Speedball 2: - https://www.mobygames.com/images/covers/l/407028-speedball-2-brutal-deluxe-dos-front-cover.jpg

Only one game I ever bought for the box art alone, without any idea what kind of game it was: Fallout. I was not disappointed. I remember the box being more red/graphic-free, though, with a prominent fallout shelter symbol, but I don't have the box any more.

Only game I had bought just because of the game box with no prior reseach was Pax Imperia: Eminent Domain when it first came out. Its being scifi 4x only helps in my favor. It was bright silver, shiny and stood out. You could open its cover flap and see more of the game inside. Sadly I don't have the box, since space was limited and I had to throw pc game boxes out.

https://www.mobygames.com/game/pax-imperia-eminent-domain/cover-art
On the US front box cover you could feel the grooves of the orbits and planets.

I always enjoyed the box art for Quake.
https://www.retrogameking.com/WebRoot/StoreNL3/Shops/78704979/5821/A7C4/F026/DC42/628A/C0A8/2BB8/E09B/DSC_4057_ml.JPG

You know, it actually stands between Dune II for PC (The building of a Dynasty, not the Battle for Arrakis cover) and Carmageddon, two of my most loved games.

Carmageddon
https://www.mobygames.com/images/covers/large/1129662450-00.jpg

Dune II: The Building of a Dynasty
https://upload.wikimedia.org/wikipedia/en/7/78/Dune2_BOD.jpg

The classic cover for Cabal for the 8-bit machines.
Also, the one for Mad TV.

Alien Isolation.

The quickest I've been sold on a game due to the box art would have to be No One Lives Forever.

doom 2, where the doom slayer has a crazy hairline.

Legacy of the Ancients had a great cover.

[url=Not PC, but the american Box for the SNES-Version of the Shoot'emUp Phalanx was kinda special

I was always a huge Dodge Viper fan, so nearly every Test Drive case appealed to me.

Original DOOM, classic.

The first Army Men games both are in there for me, since I really like the green army men. The version I got was the Freedom Pack: the first two Army Men games in the same box. They came with inserts for the jewel cases but I frankly do not remember the cases themselves being there... oh well.

The original Medieval II box also looks great along with Rome Total War.
https://upload.wikimedia.org/wikipedia/en/e/e5/Medieval_II_Total_War_pc.jpg
https://upload.wikimedia.org/wikipedia/en/7/73/Romebox.jpg

And a final shout out to Delta Force Black Hawk Down.