If a card copied by one of the tokens had any "when [this permanent] enters the battlefield" abilities, then the token also has those abilities and will trigger them when it's created
Additionally, the fact that Ancient Stone Idol leaves behind a 6/12 token with trample even if dies gives you a little bit of an insurance policy against opposing removal
To round out the token generators are the Instants and Sorceries
Other examples of cards that usually warrant grading include: Power Nine cards, generally valuable Reserved List cards, and low-print collectibles like the red neon ink Hidetsugu, Devouring Chaos from Kamigawa: Neon Dynasty or serialized cards from many recent sets
Any time you have priority, you can turn a face-down permanent you control face up by paying its disguise cost
When you hear of banned eldrazi, this is probably not the first one you think of, but it is in fact banned in Legacy