Found this thread very helpful on many occasions. Realized today it is still actively updated so I registered on CAG to contribute. Below are games I've played that I know how long it took to beat.
PS1
Metal Gear Solid - beat at 13 hours
PS2
Black - 8:30 (beat, 22%, easy difficulty)
Devil May Cry - 7 hours gametime, but it's probably closer to 10 total, I got a lot of game overs and restarted from saves
God of War - beat at 9:30
God of War II - beat at 13:30
Ratchet and Clank: Going Commando - beat 15-16 hours
Metal Gear Solid 2 - beat at 15 hours
Sly Cooper and the Thievius Racoonus - beat at 8:30, complete 100% at 13 hours
Wii
Bully: Scholarship Edition - beat at 18:20 with 76%
Metroid Prime 3 - credits at 14 hours, 65%
Resident Evil 4 Wii - 20 hours to beat