Series HH Bond

Issued from 1980 to 2004, they were more or less just like every other U.S. Government savings bond. Low rates. Low amounts. They ended up garnering low interest from the public and were discontinued...but many ran for 20 years, so they're still out there.

And for most of these and any savings bonds, once they mature, they stop paying interest. So you, uh, want to cash them the day they mature. Or you're giving yet more money to Congressmen for their little toys.