Quicksilver Amulet (Urza's Legacy) was another favorite among my casual playgroups in high school. Especially those "Timmy" players who loved their huge beasts! For some reason I thought that was a "Johnny" player, but I guess that stereotype belongs more to combo players. To round out the trilogy, "Spikes" are all about winning. And then there are those who are a mix of two or all three of the types...
But anyhow, back on track...
I kind of view Quicksilver Amulet as a staple for Commander/EDH decks, which most players stuff with large, high-casting cost creatures. The card is a great way to sneak them in when not having enough mana to do so normally. Beyond casual formats, though, I don't imagine it sees much play. It seems to have too high of a casting cost for competitive play, but there may be some brews out there.
The foil versions I have are from Magic 2012. I was excited to see them reprinted and pulled both that I own from booster packs. Maybe that particular foil was more common than others? Regardless, it's fairly inexpensive at $10 or so. Probably another card I'd like to collect a foil playset of (surprise, surprise).
Have you ever played with Quicksilver Amulet? If so, what decks do you play them in? What's the biggest creature you've cheated into the Battlefield with it? Have you known the card to be used competitively?