Ars Technica recently revealed a report showing which titles were the most popular on Valve’s Steam service, and it appears some older favorites continue to be high on the list.

Leading the group on the report is DOTA 2, Valve’s strategy title, which currently has over 25.9 million players. In close second is the classic third-person strategy/shooter Team Fortress 2 with 20.3 million, and Counter-Strike: Source with 8.9 million players.

What’s surprising, though, are that some games are owned by players, but have never been opened or activated. Source is the leading title on this list, with an estimated 3.1 million players who bought the game but never touched it. The original Counter-Strike is at an equal amount, while the zombie shooter Left 4 Dead 2 is close behind with 2.1 million.

Most of these purchases seem to stem from sales on the service, although it’s a bit odd that players don’t ever open them up, not even for an hour’s worth of play. Then again, with more popular multiplayer games like DOTA 2 and Team Fortress 2, they probably just haven’t found time for them yet.

Source: Ars Technica