Wow. Not one Clapton song mentioned, granted he's so well known and mainstream now that a lot of people overlook him. And he IS mostly known for his electric stuff, but his Unplugged album was one of the biggest sellers and live albums of the 90s. Of the stuff on that album as well as a few others:
-Old Love (one of my favorite all around tunes - awesome solo work in the bridge)
-Layla
-Change the World (smooth melody)
Other Misc tunes:
-Grateful Dead ? Friend of the Devil
-John Mayer ? ?83
-Blind Melon ? Change
-The Gourds ? Gin and Juice (just funny as hell)
-James Taylor songs ? might sound wimpy, but he's got great acoustic ballads if you ever find yourself singing/performing solo in a coffee shop type environment.