Usually this is a traditional foil card with a borderless, Ninja, Samurai, Phyrexian, soft glow, or extended-art treatment, but occasionally you'll open a foil-etched rare or mythic rare, or even a neon ink foil
Channeler Initiate has seen some play, but I am also interested in Exemplar of Strength and Baleful Ammit here
Beyond being a massive threat that can one-shot opponents, Blightsteel Colossus is also incredibly difficult to get rid of
These were in a glass showcase that most card stores use to show off their more expensive cards to customers
The Adventure side is a good mana sink, a great source of card draw and a source of artifacts that Liberty Prime, Recharged can make use of too