The buff Don Andres gives to stolen creatures as well as the Treasure tokens he generates when you cast noncreature spells that don't belong to you are nice, but they're far from enough to make stealing cards worthwhile (especially because the treasures enter tapped)
Powerline - World's Greatest Rock Star Card 233/204, Ruby Ink Truly the "World's Greatest Rock Star", you can't have The Goofy Movie in Disney Lorcana without a gnarly Enchanted card of Powerline, himsel f
Dragonstorm is also appealingly cheap right now
Lord of Atlantis This Merfolk card comes from Alpha and is just as good today as it was in 1993
The Eldrazi Incursion EDH precon has a commander who's an absolute nuisance on so many levels
For example, if a creature has three +1/+1 counters on it and two -1/-1 counters are put on it, state-based actions will remove two of each of those kinds of counters, leaving the creature with just one +1/+1 counter