I used to pull NES's out of dumpsters. Seriously.
One of the best days of my life was when me and my dad were dumpster diving, and I pulled out a garbage bag with a NES, all the cords (connectors, 2 brick controllers and a zapper), and 6 games. The power supply was broken but my dad fixed it - Sorta. The supply ended up catching fire about a month later but by then I'd already found another, thankfully in one piece and working, supply.
I found more since then, but none of them ever worked. One was smashed all to hell, another had a broken loader, and two I had no idea what was wrong with them.
I bought a SNES at a yardsale for $7. All cords, worked, and had some games.
I ended up selling all of them a few years later.
Never had a GB. Had a couple GBCs - Traded for and bought, one got stolen and I later sold the other one. As for games, all I had was pokemon yellow, pokemon silver, pokemon crystal, and some GB game that I can't remember the name of. Gave yellow to a friend, threw away silver and crystal after the battery died, and I forgot what happened to the other game.