I've got into the habit of just typing the name of anything I want to launch into Spotlight. So when I want to launch iTunes, I just ⌘+Space to open Spotlight, then type in the app name I want to launch.
Strangely tho, the last few days, the iTunes app hasn't shown up in Spotlight's result;
Normally, it shows up as Top Hit and under Applications. The app is definitely in my applications folder, and iTunes starts and runs fine from both the applications folder and from the dock icon.
I'm sure this only happened after the last iTunes update, but I could be wrong