The domination of the PC retail market by Blizzard and Maxis has been well-documented by now but one other striking thing about the sales in that market is how well very old games sell. Check out May's list, courtesy of the NPD:

1. World of Warcraft: Wrath of the Lich King (Blizzard)
2. The Sims 2 Double Deluxe (EA Maxis)
3. World of Warcraft Battle Chest (Blizzard)
4. World of Warcraft (Blizzard)
5. Empire: Total War (Creative Assembly)
6. Spore (EA Maxis)
7. Left 4 Dead (Valve)
8. The Sims 2 Apartment Life Exp. Pack / EA Maxis
9. Fallout Trilogy (Black Isle Studios & Micro Forte)
10. StarCraft: Battle Chest (Blizzard)
11. World of Warcraft: Burning Crusade Expansion Pack (Blizzard)
12. Demigod (Gas Powered Games)
13. Real Deal Slots Adventure (Phantom EFX)
14. The SimCity Box (EA)
15. Fallout 3 (Bethesda)
16. Diablo Battle Chest (Blizzard)
17. Elder Scrolls IV: Oblivion Game of the Year Edition (Bethesda)
18. Warcraft III Battle Chest (Blizzard)
19. Warhammer 40K: Dawn of War II (Relic)
20. Company of Heroes: Tales of Valor (Relic)

The Diablo and StarCraft bundles have managed to crack the top 20 for the second month in a row. The Fallout Trilogy, which includes Fallout, Fallout 2, and Fallout Tactics, had a strong May as well.