"Satisfaction," the Rolling Stones: The brute simplicity of its riff is part of its genius, but that gets wearing once you've heard the song a thousand times.
"Moondance," Van Morrison: I have all of Moondance loaded on my iPod, save the title song.
"I Got You (I Feel Good)," James Brown: For a while there, every third commercial was using this song. Now they have switched over to...
"Love Train," the O'Jays.
"Should I Stay or Should I Go," the Clash: The same basic problem as "Satisfaction," and my sons put it on every CD they burn, so I can't escape it.
On the other hand, I have listened to "Like a Rolling Stone" and "Smells Like Teen Spirit" eleventy-bazillion times apiece, and I still hear something new in them every single time.