Nancy Drew: The Phantom of Venice went straight into the US PC chart at number one for the month of July, according to the latest data from NPD.
The Sims 2: Double Deluxe was in second place with June's top-selling title, Spore Creature Creator, down to number three.
World of Warcraft: Battle Chest stayed in fourth place, while The Sims 2 IKEA expansion pack jumped two places to fifth.
Blizzard took five of the top ten positions in all, with the Diablo Battle Chest, World of Warcraft and the Burning Crusade expansion taking sixth to eighth places respectively.
The Sims 2 FreeTime was ninth, with the Warcraft III Battle Chest rounding out the top ten. Assassin's Creed: Director's Cut Edition entered the monthly chart in 16th place.
The full top ten for July is as follows:
1. Nancy Drew: The Phantom of Venice
2. The Sims 2 Double Deluxe
3. Spore Creature Creator
4. World of Warcraft: Battle Chest
5. The Sims 2 IKEA Home Stuff
6. Diablo Battle Chest
7. World of Warcraft
8. World of Warcraft: The Burning Crusade
9. The Sims 2 FreeTime
10. Warcraft III Battle Chest